Chapter
IX
THE RHETORICAL. FUNCTIONS
CHAPTER - IX L THE RHETORICAL FUNCTIONS
2.1
Introduction
II discusses certain rhetorical concepts
Chapter
to
scientific
already
discourse.
The term 'rhetoric'
'discourse'
exist in English language and are found to be useful
analysing a science subject.
Discourse is a broad
mode and rhetoric is one important part of it.
mean
and
related
communicative
By discourse,
a collection of connected language units such as
includes the way in which information is organised.
Rhetoric
It is an art
of choosing words, sentences and of arranging them in a
to
produce
a desired piece of text.
we
sentences
and paragraphs which make up a coherent, cohesive text.
manner
in
Over
coherent
the
ages,
rhetoric has been conceived as an art of effective expression, as
an
art
of
persuasion and as a discipline
concerned
with
the
problems of communicating truth and value*.
To
provide
particular
the
readers with
discourse
circulation'
units,
say,
relevant
informations
'Respiration',
on
'Blood
or 'Osmoregulation', the writer of science
follows
some techniques.
He employs appropriate words, suitable forms of
sentences
arranges
and
communicate
effectively
classifies,
instructs
and
medium,
namely, language.
studies
the
science.
*
use
them
his
in
ideas.
discourse
He
defines,
illustrates with
the
description,
in
the
to
describes,
help
In the present study, the
of the English language
Definition,
paragraphs
of
the
researcher
teaching
of
classification, instruction
Language in. Science. Thirumalai , li.S. p. 198
27
and
illustration (Visual - verbal relationship) seem to
five
major
functions of the language
in
science.
trying to do.
the
Rhetorical
function is a name given to what a particular piece of
is
be
discourse
In analysing a discourse unit of science,
the
learner might come across all the five functions of the language.
Rhetorical
techniques
scientific
materials
relationship
between
discourse unit.
of
it.
order
refer to the frame work
are
accommodated.
different
items
of
into
They
which
the
show
the
information
in arranging scientific materials.
specific
There is no
ambiguity
in his expressions as his business is to inform and not
will
knowledge.
a
The writer of science does not make a patch work
He has a well defined purpose and follows some
Ambiguity
in
hamper
comprehension
and
distort
delight.
scientific
Ambiguity or uncertainty embellish literature as
in
the following verse:
"For men may come and men may go
But I go on for ever"*
but
not
Blood
science.
For example, if the writer of
when it comes into contact with the
science
external
says,
atmospheric
conditions, may or may not change into a jelly like massj he does
a
great injury to science.
For, we know, anything which is
not
exact is not science.
During
the
functions
responded
Thus,
the research the sample class was
and
favourably
techniques
to
of
the
the rhetorical
initiated
language.
approach
the researcher's language - oriented approach
The
to
class
science.
to
gained full support from the students. It. was found that a
*
The Brook. Tennyson, Alfred.
into
science
clear
28
recognition
language
and
will
understanding
enable
of.
al 1
them to easi1v
the
-functions
comprehend
o-f
the
science.
The
validity o-f the rhetorical approach to science was appreciated by
all concerned.
The functions and sub-functions of the language are
noted
below in the rhetorical process charts
2.1 Rhetorical Process Chart
2.2
1.
Definition
2.
Description
physical, function and process
3.
Classification
complete and Partial
4.
Instruction
direct and indirect
5.
Visual-verbal
relationship
text placement and placement of
visuals
The rhetoric of definition
When
new
a
the
discourse,
terminology
and
definitions
in
word
to
present
but
writer
i□f
defines
science
it.
science.
communicated
introduces
We icome
across
They are found not
also in more advanced
the
unfamiliar
kinds
many
as can be seen from a
in science.
They are,
in
discourse.
range from a word to several paragraphs.
Generally speaking, we come across
definitions
scientific
only
in
1. Simple
of
single
elementary
writers
explanation,
an
discourse
two
a
When
needs
the terms either in a precise or
Definitions
in
They come in all sizes from
new concepts or when new technology
define
manner.
idea has to be
entire books.
textbooks
they
formal, semi formal, non-formal and
expanded
elaborate
analysis
categories
definition
of
and
29
2.
Comp1 ex
sentence
definition.
or
Simple definition is just stated
two and by complex definition we mean
definition.
Scientific
discourse offer three
definitions.
They may be stated as follows!
1.
Formal definition
2.
Semi-formal definition and
3.
Non-formal definition
Each
an
in
a
expanded
basic
types
of these provides information in different
of
amounts.
The formal definition gives us the most precise information.
The
semi-formal
the
information
gives
definition
related
does
not
provide
to the term and the
us
with
all
non-formal
definition
us considerably less information and with less
precision.
As can be seen from this analysis, we want scientific information
in
a
precise style and not otherwise.
In the teaching
rhetoric of definitions the students might be taught to
the
precise
definition of terms and also the
of
the
identify
language
use
in
them.
2.2.1
Formal definition
A
sufficient
formal
definition
information
is precise and
on the items defined.
gives
A set
the
of
formal definition is given below for analytical purposes.
Example 2.1 Formal definition
1.
Excretion can be defined as a
process by which the unwanted
nitrogenous substances are
eliminated from the body of animals.*
Source; Biological Sciences.
readers
simple
30
2.
A Catalyst is a substance which
increases the rate of a reaction
but there is no change in catalyst
(Source:
3.
Chemistry).
A solid is that state o-f matter
in which its atoms and molecules are
strongly bound, so as to
preserve their shape and volume.
(Sources Physics).
4.
Phototropism is movement o-f
curvature brought about in
plants by light.
(Source! Anatomy and Physiology
Qrowth and Movements - Botany)
It
may
be seen -from the examples
o-f
formal
definition
given above, that the writer follows an impersonal style.
Since
science defines well established fact it is stated in the present
form.
they
are
Definitions
form only bits of scientific
convey a great deal of information.
brief
Additional
further
and rigid.
Generally
That is why they are
termed
as
formal.
The definition (in a sentence or two)
into several physical paragraphs having the
but
definitions
informations regarding the defined term are given
expanding it.
expanded
discourse
by
is
definition
as the core statement.
To
term.
students
In
define is to state precisely the meaning of a word
teaching formal definitions to a science
could be shown how the different items
of
class,
or
the
information
are linguistically linked.
Diagrams followed by analysis could
be of great use to the students pursuing science at all levels.
31
2.2.1
Formal definition diaarams
—>are-y eliminated
from-^the^body-^-of > animals
Word analysis
Words
Functions
Excretion
Verbal noun - subject
can be
modal verb
defined
transitive and main verb
as
adverb
a
indefinite article
process
noun, complement
by
preposition
which
relative pronoun
the
definite article
unwanted
adjective
nitrogenous
adjective
substances
are
noun
be
32
eliminated
past form of eliminate, transitive
verb. (It takes an object).
from
preposition
the
definite article
body
direct object
of
preposition
animals
indirect object, noun
It
is the researcher's contention that
a
linguistic-
oriented study of definitions or any information in science shall
lead to an effective communication - oral as well as written.
is possible only when the learner adheres to certain
of
language
structure.
The
learner
must
It
conventions
comply
with
the
phonological, syntactic and semantic rules of the language.
2.2.2
Semi-formal definition
Semi-formal
exactly
formal.
familiar
to
the
definition as the very term suggests
Assuming that some
readers,
the writer
information
in the definition.
provide
much
as
information
informations
omits
is
are
already
certain
item
It is not complete but
as we could
get
from
definition.
Example 2.2 Semi-formal definitions
1. Taxonomy deals with identification,
nomenclature and classification of plants.
(Source! Botany - Angiosperms - Plant Taxonomy).
not
it
a
of
does
formal
33
2. Changes are introduced in the
genes either to eliminate
undesirable characters or
to introduce desirable traits
in the existing organisms.
This study is called genetic
engineering.
(Source! Zooloov - Genetic Engineering).
In
the
example
2.2 (1) the
definition
is
semi-formal
because one familiar information is wantonly omitted.
'Taxonomy
is a branch of science' is presumably known to the readers and so
is
omitted.
In the example 2.2
'Genetic
Engineering
is
one
aspect of Genetics' is omitted as the writer feels it unnecessary
to
mention.
such
In written scientific discourse we do
semi-formal
or incomplete definitions
informations
could be incorporated
communicates
the
definitions
definitions.
are suitable.
when
To
be
and
the
more
come
the
across
necessary
teacher
orally
explicit,
formal
For example, to define Taxonomy,
let
us
choose the formal definition.
"Taxonomy is Systematic Botany
-
a
deals
branch
nomenclature
of
and
Botany
which
classification
of
with
identification,
Plants".,
and
"Genetic
Engineering
is one aspect of genetic science, where changes
introduced
in
characters
or
the
to
genes
either
to
eliminate
introduce desirable traits
in
are
undesirable
the
existing
organisms".
2.2.3
Non-formal definition
In
the
analysis
of scientific discourse, one
may
come
across non-formal definitions. They are superficial and informal
style.
It facilitates easy understanding as familiar terms
34
are
used
in
the definition.
They are
not
much
favoured
in
science as they are neither wholesome nor precise.
Example 2.3 Non-formal definitions
1.
In the presence of a
catalyst. the reactions
take place
(Chemistry)
2. When ice changes into water,
it is called fusion of ice
(Physics)
3. Binomial - Bi means two,
nominal means name.
(Botany)
4. Pollution means making
something dirty or
impure
(Ecology)
From
formal
the examples stated above, we understand
definitions
informative.
information.
may
promote
comprehension
but
They reveal a superficial knowledge of
The
following
chart
shows
the
that
non-
are
not
scientific
readers
difference between non-formal and formal definitions.
the
The formal
definitions are found to be rigid, precise and more informative.
35
Example 2.4 Non—formal , formal definition chart
Terms
Non-formal
definition
Formal definition
Catalyst
In the presence
of a catalyst
the reactions
take place
A catalyst is a substance
which increases the rate of a
reaction but there is no
change in the catalyst.
Fusion
When ice
changes into
water it is
called fusion
The process in which a solid
changes
into a liquid
on
heating is called fusion or
melting
Binomial
Binomial - Bi
means two;
nomial means
name
All
the names of
plants and
animals
are
known
by
a
combination of only two words,
the first word refers to the
genus
and the second
one
refers
to
the
particular
species to which the plant or
animal
belongs.
This
is
termed as
"Binomial".
e.g.
Rosa Canina.
Pollution
Pollution
means making
something
dirty or impure
Pollution
is an
undesirable
change
in
the
physical,
chemical
or
biological
characteristics of air,
water
and land caused by industrial
waste, automobile exhaust etc.
The
of science must not be
learners
definitions .
expressions ,
They
should
synonyms
learn
A
definitions
writer
by
twisted
careful in choosing words and organising them in proper forms
of
can be seen in examples given
Even semi-formal definitions are
of
incorrect
is
non—formal ones
antonyms.
by
science
sentences as
definitions
or
not
lead
under
'formal
preferable to
36
2.2.5
Complex definition
By
writer*
complex definition we mean expanded
expand
examples
the definition in more than
but
formal.
They
are
paragraph
from
more
informative
Example 2.4. Complex definition
The blood remains in a fluid
state as long as it is inside
the blood vessels.
But when it
comes into contact with the external
atmospheric conditions, it changes
into a jelly like mass.
The blood
is then said to be clotted or
coagulated.
.......The blood clot plugs
the opening of the injured
vessels and thus prevents
the further loss of blood
This property of blood serves
the important purpose of
reducing the loss of blood in
case of injury.
.......Our knowledge of the
understanding of the process
coagulation is
mainly due to the
pioneering work done by Howell
on the blood of Limulus
of
Howell's Theoryt
According to Howell, the
clotting of mammalian blood takes
place in two distinct stagesj
(1) Formation of thrombin from
prothrombin existing in the
plasma.
(2) Action of thrombin of fibrinogen
whereby fibrin is formed,
prothrombin is supposed to be
converted into thrombin by the
action of calcium alone.
The
The
and
scientific
Complex definitions
descriptive.
'
one
of this kind of definition can be had
discourse meant for higher levels.
simple
definition.
as
are
well
not
as
37
blood does not clot in the
body because of the presence of
antithrombin which prevents the
activation of thrombogen or
prothrombin.
Howell's Theory of Coagulation
Blood*
Plasma
Corpuscles
When the blood vessel is injured,
the tissue cells- produce a
substance known as cephalin protein.
This reacts with fibrinogen
to form fibrin.
description,
Explication,
exemplification
definitions
the
students
definitions.
*
are
the ways by which the
in science,
could
classification
be
They also
writers
expand
While teaching these items in
trained
need
to
to be
identify
taught
the
to
and
the
science,
variety
recognise
Animal Physiology. Itta Sambasiviah, Kamalakara Rao,
and Augustine Chellappa, S. pp.97-99
of
the
38
difference in the amount and preciseness of information given
each type of definition.
by
It could be seen that formal definition
alone provides the most information on a given item.
2.3. The rhetoric of description
Description
across
are
plays an important role in science.
physical, functional and process description.
not
water-tight
description
seem to overlap also.
kind of information.
physical
compartments.
These
But
three
Each type gives
We
come
these
types
a
different
For example physical description gives
characteristics
of an
object.
Function
of
the
description
describes the purpose or use of an object or organ and the way in
which
each
description
of
the
parts
and
the
whole
function.
describes steps of a procedure and the goal
Process
of
the
descriptions of tools and apparatus, organs
and
procedure.
2.3.1. Physical description
Physical
object are found in all the scientific texts.
function
and the process, a learner has to be well
the physical nature of the said organ.
the
To understand
of the ear and its function are necessary.
The Ear
The ear is the organ of hearing
and maintenance of equilibrium
of the body.
The ear is made
of
For example to understand
process of hearing, a knowledge of the*physical
Example 2.5. Physical description
informed
the
description
up of three parts.
1. The External
ear, 2. The middle and 3. The
internal.
The external ear consists of an
expanded portion called pinna
which is supported by cartilage
and the external
auditory meatus which forms the
canal leading to the tympanum
or ear drum.
Hairs and waxy
secretion within the canal help
in preventing the entry of dust
particles and small insects.
Skin lines the canal.
Following the tympanum or
ear drum is a flexible cavity in
the middle of the ear.
This is
the region of the temporal bone
of the skull.
This cavity contains
a chain of three bones i.e. malleus,
incus and stapes which communicate
with the inner ear through an overall
opening known as fenestra ovalis.
Fenestra rotunda is another round
opening present just beneath the
other.
Malleus is hammershaped,
incus anvil- like in form and the
stapes is in the form of a stirrup.
The middle.ear communicates with the
pharynx through eustachian tube.
It
serves to equalize the pressure on both
sides.
Hearing will be normal only
if the pressure is equal both in the
external and middle ears.
The inner ear consists of a
membranous labyrinth.
It has three
semi-circular canals, one horizontal
and two vertical, and a vestibule
with two sacs known as utricuius
and sacculus followed by cochlea.
One end of each semi-circular canal
is swollen to form the ampulla.
Otolith
organs present within the semi-circular
canals are concerned with the maintenance
of equilibrium.
The organ of corti
present within the cochlea
receives and conducts the sound stimuli.
Auditory nerve has branches
over the vestibule, the semi-circular
canals and over the cochlea.
Stimuli
40
for the maintenance of equilibrium and
sound waves are respectively transmitted
to the brain by the auditory nerve*
As
can
be
seen from the example
given
above
descriptions state the use of the organ described, its
physical
positioh,
shape and location in specific terms.
2.3.2. Function Description
Function description is another rthetorical function.
It
states the function of the object described.
Example 2.6. Function description
By virtue of its circulation through
every organ, the blood participates
in every major functional activity of the
body.
The various functions of the blood
are as follows:
(1) The Transportation of Oxygen and
Carbondioxides:
By virtue of the presence of
haemoglobin in red blood corpuscles,
blood plays a notable part in respiration.
The transport of Oxygen from the lungs
to the different parts of the body
and the transport of carbondioxide from
the tissues to the lungs is effected mainly
because of the Oxygen - Carbondioxide
carrying capacity of blood.
(2) The transportation of food
materials:
The digested food materials,
viz., the amino-acids, glucose,
fat acids etc., are obsorbed by
the blood vessels present in the
intestine and are then transported
to different parts of the body
*
Animal Physiology- Itta Sambasiviah,
and Augustine Chellappa,S. p.209.
Kamalakara
Rao,A.P.
41
where the cells make use of them
for the building up of the body
and for the production of energy.
<3) The transportation of waste
materials!
As a result of Katabolism,
waste products like urea, uric acid,
creatine, creatinine, water and
Carbondioxide are formed in the
body and they must be removed, for
otherwise they prove to be injurious
to the body.
The removal of waste
products of metabolism from the place
of their formation to the site of
excretion (Kidney or skin or lung)
is affected by blood.
(4) Regulation of body temperature:
Sweat plays an important
role in the maintenance of body
temperature.
The flow of blood
to the sweat glands is responsible
for the production of sweat.
If more blood is supplied to the
sweat glands, more of sweat is
produced and vice versa.
The
flow of blood into the sweat gland
is controlled by the nervous
system.
Thus the blood plays an
indirect part in the maintenance
of temperature. The blood serves
to distribute the heat generated
in the voluntary muscles during
oxidation of the food materials*
2.3.3. Process description
Process
in
a
process.
description refers to a series of steps
Often a process description gives
a
involved
series
of
instructions.
Usually, imperative forms of verbs are used in the
rhetoric
process description.
of
It includes
all
the
steps
leading to a goal.
*
Animal Physioloov. Itta Sambasiviah, Kamalakara Rao.A.P.
Augustine Chellappa,S. p.93
and
42
Example 2.7 Process description
The afferent artery enters the
glomerulus carrying oxygenated
blood which contains waste materials
like urea and sodium salts besides
useful materials like glucose.
Urine is filtered off by the
Bowman's Capsule from the
glomerulus. Even the glucose finds
its way into the uriniferous tubule.
The efferent artery leaves the
glomerulus takig the pure blood
devoid of urine and branches over
the uriniferous tubule in the
form of a network of capillaries.
In doing so, it supplies oxygen to
the region and takes back carbondioxide
from there. Alonmgwith Carbondioxide
Glucose is also reabsorbed.
It now
leaves as vein containing impure blood*
While
teaching the rhetoric of description
the
students
may be directed to identify the kind of description and also
the
language
are
use.
The language use in the rhetoric
functions
dealt with separately in Chapter - IV.
2.4
The rhetoric of classification
The
Like
rhetoric of classification is worth
definition
it
is
so
basic
basic to scientific expression.
definition
relationship
is
quite useful.
between
to
human
examining
thinking
Teaching classification
here.
and
so
through
Students will very quickly see the
the two and equally quickly
are
able
to
verbalize them.
*
Animal Physiology. Itta Sambasiviah,
and Augustine Chellappa,S. p.129.
Kamalakara Rao.A.P.
43
There
are
sharp
contrasts
between
the
-functions
definition and classification deals with all members.
of
Definition
isolates the term described whereas classification deals with all
the
members
of
the
class.
We may
identify
three
types
of
classification, viz.,
1. Complete classification
2. Partial classification and
3.
2.4.1
Implicit classification
Complete classification
Complete
classification provides the readers
with
three
main informations! They are as fallows:-
1.
the items being classified
2.
the class to which the items belong
3.
the basis for classification
The
suggests
specify
the
first
gives us the names of two or
terms
and
that there is a relationship between them but does
not
precisely what this relationship is.
class
more
The
to which the members belong and gives
information on the relationship between them.
second
us
additional
The third tells us
in what way the members of the class differ from one another
may also tell us in what way they are
related
-
although
information may be suggested by the class itself.
Example 2.8
Complete classification but open ended.
The names for teeth in all
mammals are based on appearance,
function or position of the
names
and
this
44
equivalent human teeth: they are
incisors, canines, premolars and
molars*.
The
ended.
It
given example is a complete classification but
It gives information about the item
also
states
appearance,
open-ended
the
basis for
the
function or position.
(teeth)
classified.
classification
We call
open-
of
teeth-
the given example
classification because it provides means for
an
further
expansion of classification.
2.4.2
Partial classification
Classification
is
for
seem
called partial
classification.
granted and the classification
classifying
Sometimes the basis is
is bluntly
stated.
to do so as they feel that the basis is obvious.
Classification
one.
that leaves out the basis for
without the basis shall
be taken as
The information given under such a partial
an
taken
Writers
But
improper
classification
cannot be understood wel1.
Example 2.9 Partial classification without a basis
The modern algologists classify
algae into 11 divisions.
They are
Cyanophyta, Chlorophyta, Charaphyta
Xanthophyta, Chrysophyta, Baci1lariophyta,
Pyrrophyta, Cryptophyta,
Euglenophyta, Phaeophyta and
Rhodophyta.
These 11 divisions are
further divided into classes,
orders and families.**
*
**
Anatomy.
Gray,
1989:1302
Biology. (Higher Secondary Second year),
Text Book Society, p.69
the
Tamil Nadu
45
can
be
seen
classification
is
without
As
learner will
from
example
a basis.
have difficulty in
Example 2.10
the
It
stated
is
above
superficial.
the
The
learning them
Partial classification with its basis
unstated but obvious
The
Eumocophyta
or
true fungi
are
divided
into
four
classes, viz. ,
1.
Phycomycetes, or alga like fungi,
in which spores are
usually produced in sporangia.
2.
Ascomycetes,
or
sac fungi,
in which the
spores
are
produced in asci.
3.
Basidiomycetes, or basidium fungi
in which the
spores
are
produced,
usually
in fours,
on
a
specialised
structure known as basidium.
4.
Deuteromycetes
or
Fungi
imperfecti,
in
which
the sexual or perfect
stage is not entirely known.*
The
example
quoted
above is
a
partial
classification
because the basis for classification is not stated here but it
is
obvious.
type
of
not
in
spores,
2.4.3
The fungi
are classified on the basis of the
they produce.
Implicit classification
Implicit
classification
classification terms.
paragraph
a form
but
We come across such classification in
structure in scientific discourses.
taught to pick out the items of
*
classifies
Students
can
information that go to make up
the
be
a
Biology.
(Higher Secondary Second year), Tamil Nadu Text
Book Society, p.77
46
classification.
Exercises of this sort will enhance the pleasure
of learning science generating interest in students.
There are a
number of ways with which students can be helped to learn how
to
abstract
a
out
the
necessary
classifying
scientific discourse. One way is to
of
the
follow
items
each
information
from
write down the names of each
of information expected
from
a
classification,
name with a blank and then find terms
that fit the names and so fill in the blanks.
Example 2.11 Implicit classification
man has used solids of various
kinds from very ancient times
but it is only in this
century he has gained
a satisfactory understanding
of the way constituent atoms
arrange themselves in a solid.
A solid may be amorphous or
crystalline.
You have
come across commonly
occurring crystals like sugar,
rock salt, mica, quartz and
gems.
These crystals have
symmetrical shapes and
flat faces which meet at
characteristic angles.
Most
of the solids which do not
appear to be crystalline
to the naked eye, are
actually found to be aggregates
of small crystals, when
examined under a microscope.
To describe the structure of
a crystal, we do not have to give
positions of all the atoms in the
crystal.
The arrangements
of atoms in a crystal
can be described by choosing
a smal1 group of atoms and
imagining them to be located
in a cell.
The present day
advances in electronic
technology are in a sense
and
phrases
47
outcome of the in depth
study of solids.*
Using the information given in the paragraph quoted above,
we
can
visually illustrate the classification implied
in
this
paragraph as follows:solids
*
—-------------- *
Crystalline
amorphous
(A crystalline solid is one
which has regular and periodic
arrangement of atoms or molecules
in 3 dimensions)
------------
------------------------------------
'
(e.g) Sodium, Chloride
diamond, lead etc.
2.5
(e.g) glass, rubber,
plastics, etc.
The classification tree and
discourse of science.
A
more
its
significance
visual form of recording the
informations
given classification is the classification tree.
useful
the
of
informations
sort
It is the
visual for the students to understand their
help
of
the
classification
tree,
they
communicate
their
exercise
ideas.
to
the
students
They learn to
It
of
frame
rearrange them coherently in paragraph writing.
text.
can
for oral as well as written purposes.
language
in
the
of
a
most
With
extract
gives
a
science to
sentences
and
To classify well
requires more understanding of the concept of classification than
does
just
instruct
recognizing
the
students
what a writer is
regarding a set of
writing paragraphs of classification.
classifying.
rules
to
We
use
can
when
If the rules are neglected
the result will be disorderly mish-mash of details.
Physi, cs. (Higher Secondary - Second year), Tamil Nadu
Text Book Society, p.360
48
2.5.1
Rules for classifying
1.
There
belonging
should
to a class.
be
a
basis
for
classifying
members
The relationship between the members
and
the class should be stated.
2.
A class must have atleast two members.
3.
In larger classes, only the necessary members
stated.
4.
Each member of a class must be clearly separated
the other members of the class.
need be
from
Example 2.12 the classification tree
movements*
1
l
Autonomic or
)
spontaneous
Paratoni
induced
r
Tael
movements
a.
b.
c.
d.
Locomotory
Nutation
Cyclosis
Growth
movements!
epinasty and
hyponasty
e. Turgor
movements:
f. Hygroscopic
movements:
hydrochasy and
xerochasy.
2.6
a.Phototax is a.Geotropism
b.Chemotaxix b.Phototropism
c.Thermotaxis c.Hydrotropism
d.Chemotropism
e.Thigmotropism
ili c
Nasi
movements
a.Photonasty
b.Thermonasty
c.Nyctinasty
d.Seismonasty
The rhetoric of instructions
Generally,
laboratory
*
Tropic
movements
r
or
the
manuals
rhetoric
for
of instructions
science.
We
are
are
found
concerned
Anci11arv Botany. Rao, K.N., Krishnamurthy, K.V. and
Sudhakara Rao, G. 1983:467
in
with
49
instructions
analysis
of
instructions.
we -find them to be
science
text
books
informative
reveals
two
too.
An
kinds
of
They may be stated as follows:
1.
direct instruction and
2.
indirect instruction
By
'instruction'
Usually,
most
because
we mean tell someone to
do
something.
we find direct instructions in a vertical list that
often
headed
by a sentence indicating
the
goal
of
is
the
instructions.
In indirect instructions, the discourse is usually
in
form.
paragraph
The core statement of
indicate the goal of the instructions.
the
paragraph
Examples are given
to illustrate direct and indirect instructions respectively.
2.6.1
Direct instruction
Example 2.13 direct instruction
(Rationale scheme for identification.)
Main test listed in the order in
which they are to be performed.
1.
Hay's Test for bile-salts
2.
Addition of IX Acetic acid
drop by drop for casein pptn
3.
Biuret Test-for all proteins
4.
Iodine Test for Polysaccharides
5.
Benedict's reduction Test for
reducing sugars
6.
Benedict's reduction Test, after
Hydrolysis and neutralising
hydrolysate - for sucrose
7.
Hypodromite Test - for urea.
8.
Benedict's Test for uric acid.
will
below
50
9.
Jaffe's Test - for creatinine
10.
Ammonium molybdate Test - for
phosphates.
Note; These tests must be performed
exactly in the order given without
skipping any test.
If test No.11
for casein is skipped,
it might
lead to the detection of a
Coagulable metaprotein by giving a
false positive coagulation test.
If
test No.IV (Iodine Test) is missed
it might end in the detection of a
reducing sugar or sucrose.
If test
No.5 for proceed directly to Test
No.11, when test No.11 is also
negative, proceed with test No.Ill
and so on.
When you come to one of
the main tests which proves positive,
do the confirmatory tests mentioned
under the main test in the scheme
Do not proceed further with the
other main tests, unless you are
asked to find two substances in the
same solution.*
From
information
Cautions,
the
given
provides
warnings,
example,
its readers
specifying
theoretical considerations.
we
find
with
that
instructional
corollary
statements,
informations
description
The directions follow an
and
imperative
style.
2.6.2
Indirect instruction
Example 2.14 indirect instruction
Beotrooism
AIMs
To demonstrate geotropism in plants
using clinostat apparatus.
*
Practical
Biochemistrv
edition) 1985, p.88
for
Medial
Students.
(Revised
51
ftpparatauss
A clinostat, Potted Plant.
Procedure!
The clinostat consists of a
clockwork which rotates a disc
attached to it by means of
an anil rod. A potted plant is
fixed to the disc and the apparatus
is placed in a horizontal position
and the clockwork started. The disc
along with the potted plant
rotates
on its axis at the
rate of 1 to 5 rotations per
hour.
Note the changes in
stem and root tips. Then stop
the clock
and
allow the plant
for
some days.
Note
the
changes in stem and root tips.
Observation!
No curvature of the
root or
stem tip is produced when it
rotates.
The stem tip grows
against to earth gravity
and root grows towards earth
gravity
when
the stop clock
works.
Inference!
Since
the potted
plant is made
to rotate on its axis, all
sides of the plant
successively come to receive
the geotropic stimulus
equally.
Hence,
no curvature
has been produced.
When the stopclock works the
geotropic stimulus acts on
stem and root in one direction
and the stem grows upward and
root grows downward.
This
proves geotropism in plants.*
*
Bioloqv.
Practical Work Book
(Higher
Second year), Winny Publications, p. 17
Secondary
Course,
52
From the example of indirect instruction stated above,
it
can be seen that indirect instructions are stated in a paragraph.
They
use non-imperative verb forms.
passive verbs,
modals
and
passive modals are commonly used in indirect instructions.
2.7
The rhetoric of Visual - verbal relationship
The
visual - verbal rhetoric is an important
all
scientific discourses.
and
graphs are the visuals usually found in
The
rhetoric
visuals
and
discussed
the text.
feature
Drawings, diagrams, tables,
here
shows
the
charts,
discourse
writing.
relationship
We come across several types
in
between
of
visual
aids in scientific writing and each type provides the reader with
its own kind of information.
But all these seem to share
common
characteristics:
1.
They provide information in a brief but detailed
manner.
2.
They relievethe readers from
reading a lengthy text,
3.
They provide us with details that are found
difficult to express in words alone.
However,
visual
without
can
some
provide
kind
of text
information
the
tediousness
explanation
with
the
same
to
no
type
clarity
of
be
of
and
precision that well-written scientific discourse does.
2.7.1
Rules for the placement of visuals
1.
If the visual is of direct importance to the text,
should be placed on the same page with the text.
2.
If the visual
page.
is big it can be put on the
it
following
53
3.
Visuals can be put at the end of a chapter
are several related visuals.
if
It could be seen that in some cases, texts determine the
and in others, visuals determine the texts.
there
visuals
However, the
verbal
and the visual information usually complement one another.
2.7.2
Visual - verbal relationship (description)
Here
an
attempt
is made to show
the
visual
-
verbal
relationship with regard to the rhetoric function of description.
Science
is
visuals
of some kind.
the
descriptive and no description is
relationship
discourse.
possible
without
Examples that follow this paragraph
between
figures
and
texts
in
show
scientific
Each example is followed by a bit of explanation
the researcher.
Example 2.15 Visual aid for the rhetoric of description
(Physical)#
Resonance column apparatus
The resonance column *apparatus
consists of a glass tube (6)
about metre long and 5 cm
in diameter, Open at both ends
and fixed to a vertical board.
The lower end of the glass tube
is connected by a rubber tube (T)
to a reservoir of water.
By
moving the reservior (R) up and
down along the vertical
board,
the level of water in the glass tube
can be adjusted (Fig.2.1).
*
Physics. (Higher Secondary, Second year), Tamil Nadu
Text Book Society, p.85-86.
by
54
li j»-AM
r
—-------
■
bJ
f
i
l
G
1
*W
1
1
\
w
•*
'
'
*
FW . Resonance apparatus.
Fig.2*1 Resonance Apparatus*
In the given example, the rhetoric specifically
an
the
apparatus and therefore, the writer gives the
apparatus
diameter'.
by using terms like 'about',
describes
dimensions
'long' and
'5cm
In this context, it is the text that determines
of
in
the
visual
*
Physics (Higher Secondary - Second year), Tamil Nadu
Book Society, p.86.
Text
55
Example
2.16 Visual aids for description (Physical
functional)
The Kidneys
The kidneys are dark, red, bean
shaped structures placed one on
either side of the median
vertebral column in the lumber
region. Each kidney is about 4
1/2 inches long. 21/2 inches
broad and over one inch thick.
The right kidney is slightly on
a lower level than the left.
This is due to the fact that
the right side of the abdominal
cavity is occupied by the
liver. The outer surface of
the kidney is convex while the
inner is concave and it faces
the inner concave region
known as the hilus. A slender
muscular tube known as ureter
takes its origin at the hilus
and runs backwards to join the
urinary bladder.
It serves to
conduct the urine from the
kidneys to the urinary bladder.
The renal artery and renal vein
pass in and out at the hilus.
The former branches out from
the dorsal aorta and the latter
joins the inferior vena cava.
The two kidneys together
contain about 2,400,000
nephrons and each nephron is
capable of forming urine by
itself. The nephron is
composed basically of (1) a
qlomerulus from which urine is
filtered, and <2) a long tubule
in which the filtered fluid is
converted into urine on its way
to the pelvis of the kidney.*
*
Medical Phvsioloav. Guyton, p.393
process
and
56
Fig.2.2
kidney and
1
plan o-f
a nephron.
figure 34-1. The general organizational plan of the urinary
system.
Fig. 2.2 The Organisation Plan o-f the urinary system.
Fig. 2.3
The Structure of the nephron
the
57
From the text
be
like
seen that the writers describe the
shape,
described.
as
(example) accompanied by the visuals, it can
well
colour,
strength,
physical
location
etc.
characteristics
of
the
items
Visuals help to describe the physical characteristics
as process and functional descriptions
of
the
object
described.
Example, 2.17
Visual that determines the text.
ft.C. Generator*
An
of
1.
2.
3.
4.
A.C.
Generator essentially consists
four main parts.
field magnet
armature
slip rings and
brushes
Fig. 2.4 A.C. Generator and induced ACEMF
*
Fhvsics. (Higher Secondary - Second year), Tamil Nadu Text
Book Society, p.216
58
(i)
Field magnet
In the figure shown above NS is
a powerful magnet called the
field magnet which produces a
strong and uniform magnetic
field of induction B between
its poles N and S. It is a
permanent magnet of the horse
shoe type in a small dynamo and
strong electro magnet in the
case of a generator producing
large set.
(i i)
ftrmature
The armature <PQRT) consists of
a number of turns of insulated
copper wire wound over a
cylinderical drum of soft iron.
This is rotated about an axis
in its own plane and
perpendicular to the magnetic
field.
(iii)
Slip rings
The two ends of the armature
are connected to two metal
rings SI and S2.
As the coil
rotates in the magnetic field,
these rings also rotate along
with it and hence are known as
slip rings.
(iv)
Brushes
The carbon or metal brushes B1
and B2 kept pressed against the
slip rings SI and S2
respectively are used to carry
the current generated in the
armature to the external
Circuit.
According to
Fleming's Right hand thumb
rule, the induced current flows
from P to Q.
Since R.T. moves
up, the induced current flows
from R to T.
59
From the figure4 (2.4) given above, we may notice that the
visual in this context determines the text.
physical
uses
description
the
effectively
The
visual
To proceed with
of A.C. Generator in Physics,
(A.C.
communicate.
markings on the visual
Generator
and
induced
the
the
writer
ACEMF)
Here, the visual determines the
(NS, PQ, RT, SI, S2, B1, B2,
to
text.
2T
3T) help him to perform the rhetoric of description.
Example 2.18 Texts determine visuals
Newton's Rinas
An important application of
interference in thin films is
the formation of Newton's
rings.
It was observed by
Robert Hooks that when a convex
lens of large radius of
curvature is placed on a plane
glass plate and the planoconcave
air film between them is viewed
under white light, the point of
contact is surrounded by a set
of coloured rings. Newton made
a systmatic study of these
rings and even measured the
radii of the rings. These
rings are known as Newton's
rings. WHen the film is viewed
under monochromatic light,
alternate bright and dark rings
are observed around the point
of contact, which appears dark.
tharathlar University
Library
LINGUISTICS
and
60
Fig. 2.5 Newton's Rings apparatus*
Fig 2.6 Newton's Rings
*
Physics. (Higher Secondary - Second year), Tamil Nadu Text
Book Society, p.155.
61
The writer o-f
across
text
science to put his ideas
the students,
in
<on Newton's rings)
uses the diagrams and so,
this context determines the diagram o-f
we say
that
Newton's
the
Rings
apparatus and Newton's Rings.
Example 2.19
Visual
that
shows
inseparable.
(All
diagram
vividly
are
without the other
the
how the content and the
seventeen
described in
i terns
the
diagram
are
below
the
Therefore,
one
mentioned
text.
is invalid.
Fig 2.7 Shapes o-f Leaves
62
Example 2.20
Visuals that imply classification
Climbina plants*
There are two classes of cl imbing plants viz., the Twiners
and the Climbers
1. Twiners
Fig 2.8 Twiner (Bean)
Fig.2.9 Tendril Climber
(Passiflora)
2. Climbers
(Smilax)
Fig. 2.10 Tendril Climber
(Smi1 ax)
*
Fig. 2.11 Tendril Climbers
(Pea)
Anci11 ary Botany. (A Text Book for Degree classes,
Rao, K.N., Krishnamurthy, K.V., and Sudhakara Rao, G
1983:28
63
Fig 2.12
Leaf Climber
(gloriosa)
7?
Fig. 2.13 Petiole Climber
(clematis)
B.Hook Climbers
Fig. 2.15 Hook Climber
(Bauhinia)
Fig. 2.14 Tendril Climber
(Antigonon)
Fig.2.16 Hook Climber
(Artaborys)
64
C.
Thorn Straaalers
Fig. 2.1? Thorn Straggler,
(Solanum trilobatum)
From . the
technique
science.
of
example given above, it can be
visuals
is the best
technique
seen
of
that
the
communicating
Visuals enrich the subject matter discussed and enhance
the pleasure of reading science.
2.7.4
Visual-verbal relationship Cinstructional)
It
visuals.
books
as
is
not unusual to see
scientific
instructions
with
We come across visuals with instruction in science text
well
as manuals.
Visuals
accompanying
instruction
reinforce the information found in the rhetoric of instruction.
Example 2.21
Visual with indirect instruction
Preparation of acetone*
Laboratory preparation
when calcium salts of fatty acids
are distilled ketones are produced
When calcium acetate is distilled
acetone is obtained.
A mixture
of calcium acetate and anhydrous
sodium acetate is taken in a
*
Chemistry, (Higher Secondary - Second year), Tamil Nadu Text
Book Society, p.85.
flask filled with a one
holed stopper.
A delivery
tube is passed through the
hole and the other end is
kept in a receiver through
an adapter.
The mixture
in the flask is first heated
slowly and then strongly.
Acetone distills over and
collected as a liquid.
It
is contaminated with impurities
such as tar.
The impure
acetone is mixed with sodium
bisulphate and the solid
derivative of acetone is
filtered and distilled.
The
distillate collected at a
temperature of 328-329K is
pure acetone.
Fig. 2.18 Preparation of Acetone
1. calcium acetate +
Anhydrous sodium acetate
2. Water
3. Acetone