NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
18
The principle of the method is to find the particular dilution of a nor-
mal solution of sodium chloride, two volumes of which will exactly
cause hæmolysis of one volume of the blood. Let this dilution be
N / 4 5 ; t h i s i s e q u i v a l e n t t o a 0 . 1 3 0 p e r c e n t . s o l u t i o n N a C l .
Now, in a similar way the dilution of the serum with distilled water
necessary in order that two volumes of the diluted serum may
cause hæmolysis of one volume of blood is found.
Therefore we have for example
:—
N/45 Serum/8 = 130% NaCl therefore Serum=1.040% NaCl.
On Table VI we presert the results obtained in 84 different observations
on the total salinity of the serum.
Table VI.
Serial
No.
No. of
observations.
Dilution of normal
solution of NaCl,
two vols. causing
hæmolysis of one
vol. blood.
Dilution of serum
necessary for
two vols. to
hæmolyse 1
vol. blood.
Total salt
concentration
of serum.
Class.
Per cent.
Per cent.
1
40
N/45=.130
7.94 fold
1.033
Student.
2
7
N/4910=.119
9.00 „
1.071
Dome
& Mehtars.
3
37
N/52.54=.1112
9.52 „
1.058
Mixed
Classes.
(d) A fourth means of examination—for a knowledge of which our thanks
are due to Captain Harvey, I.M.S., and Captain McKendrick,
I . M . S . , b o t h o f t h e P a s t e u r I n s t i t u t e , K a s a u l i , t h e o r i g i n a t o r s o f
the method—was made use of to estimate the total chlorides of the
serum. (3) Captain Harvey was good enough to demonstrate the
technique before the method was published. Shortly, it consists
in the titration of a known solution of AgNo 3 against the serum—
a thin strip of chromate paper acting as indicator. Its great ad-
vantage is that the estimation can be carried out with so small an
amount as 50 c.ms. of serum ; specially graduated capillary
pipettes being essential.
(3) Harvey and McKendrick—Scientific Memoirs, No. 30.
19
We have found it better to use as large an amount of serum as possible
so long as the serum is clear ; the error of observation is thus
reduced to a minimum.
The average amount of chlorides present in the serum of the Bengali
over a large series of investigations by this method works out at
from .70—.78 per cent.; varying within very narrow limits.
Now, let us examine the results arrived at from these different methods of
investigation :
—
i. From the chemical composition shown on Table V it is evident that the
proteid content is on a lower scale in the Bengali compared with
the European.
This is in spite of the fact already shown that the corpuscular element
is increased in the Bengali ; it is, therefore, evident that the defici
ency in the floating proteids of the serum is even greater than
would appear from the table. When we recollect that it is from
these floating proteids—serum globulin and serum albumen—that
t h e d i f f e r e n t n i t r o g e n o u s t i s s u e s o f t h e b o d y d e r i v e t h e i r n u t r i t i o n ,
it will be abundantly apparent that these facts have a very import-
ant bearing on the sufficiency or otherwise of the diet and more
particularly of the proteid element in that diet.
In this connection it is interesting to note that a sparing diet (1½ litres of
milk a day) will cause a marked diminution in the amount of serum
albumen and serum globulin in so short a time as a week.( 1 )
ii. The total concentration of the serum or its total salinity.
From a comparison of Tables V and VI it will be found that the quan-
titative estimation of the salts corresponds closely with the per-
centage obtained by Wright's hæmolysis method—1.06 per cent.
and 1.054 per cent.
Professor Wright holds that what is measured by his methods is proba-
bly the chlorides (2) and not the total salts ; to this we are unable to
agree. We have found that the salinity of the serum as shown by
the hæmolysis method is always greater than the percentage of
chlorides estimated in the way devised by Harvey and McKendrick
already mentioned. This is strikingly borne out by some experi-
mental results obtained from the effect of small or large doses of
quinine sulphate on the concentration of the serum in healthy
adults. The typical results of a few observations are shown in
Table VII.
(1) Landau—Osmostischen Druck des Blutes.
(2) The Lancet—2nd April, 1904.
D 2
20
Table VII.
Serial
No.
Total concentra-
tion of serum
by Wright's
method.
Chlorides of
serum by
Harvey-
McKendrick
method.
Quinine Sulph
given
thrice daily.
Total
concentration
of serum by
Wright's method.
Chlorides of serum by
Harvey-McKendrick
method.
Per cent.
Per cent.
Per cent. Per cent.
1
. 8 7 5
. 7 2 8
2
. 9 2 8
. 7 3
3
1.06
. 7 5
4
1.07
. 7 6 3
Gr. V.
. 9 6 5
. 724
Consecutive
days from
8th August
1907.
4
. 9 6 5
. 7 2 4
„ V.
.914
. 723
4
. 9 1 4
. 7 2 3
„ V.
.863
. 7 0 5
4
. 8 6 3
. 7 0 5
„ X.
.701
. 612
4
. 7 0 1
. 6 1 2
„ X.
.876
.720
4
.876
. 7 2 0
„ X.
1.061
. 7 5 8
4
1 . 0 1 6
. 7 5 8
„ XX.
1.04
. 754
[Many more observations were made on the effects of quinine sulphate in
health and the invariable result found was the immediate decrease
in the salt concentration of the serum—a negative phase—followed
by a return to the normal degree of salinity. The effect of quinine
sulphate would therefore appear to be to lessen the resisting power
of the red blood corpuscles to hæmolysis ; and the larger the
dose the more quickly this resisting power is reduced. The
bearing of these results on the administration of large doses of
quinine sulphate as a factor in the causation of hæmoglobinuria is
obvious and opens up a very interesting problem.] (1)
In Europeans the total salinity of the serum is .90—.95 per cent. Many
authorities, however, give a lower value. In the Bengali the
figures vary from 1.05—1.09 per cent. Wherever there was any
appearance of anæmia we always found the salinity increased,
while, on the other hand, the healthier the individual looked the
lower the salt concentration of the serum turned out to be.
(1) McCay—Ind. Med. Gazette, February 1908.
2I
It has been shown (1) that in pathological conditions the salinity,
measured in this way, is greatly increased in œdema and anæmia.
The lower percentage of hæmoglobin present in the blood of the
Bengali would appear to have a distinct connection with the higher
salt concentration of the serum ; the salinity of the serum varying
inversely as the hæmoglobin value of the blood. What the ex-
planation of this is we are unable to say. It would appear, how-
ever, that in those diseases in which the salt concentration of the
serum is markedly increased —anæmia, Bright's disease, etc.—the
red blood corpuscles are more resistant to a dilution of the serum
than in health. That this is not due to a retention of chlorides
by the blood is evident from the fact that, although estimation of
the total chlorides of the serum by the Harvey-McKendrick
method shows a decided increase, the increase is nothing like
sufficient to account for the very high percentage obtained by
Wright's hæmolysis method. Some other factor, at present
undetermined, increasing the resisting power of the red blood
corpuscles and which cannot be explained by osmosis or mere isoto
- n i c i t y , m u s t b e p r e s e n t . H o w e v e r , i n h e a l t h o r e v e n i n t h e d e g r e e
of anæmia met with in the Bengali, the results can be completely
explained by osmosis ; the proof of this statement will be found
in the close agreement of the percentage of total salts estimated by
the ordinary quantitative means and by Wright's hæmolysis
method.
iii. The chlorides of the serum
—
Voila's average value for human blood serum—0.55 per cent, NaCl—agrees
very closely with the faultless results obtained by Schmidt,
Wannach and Biernacki. (2) This is the quantity usually accepted
for the blood serum of Europeans. Landois (3) gives the total in-
organic salts of human blood serum at .85 per cent., the chlorides
alone being .50 per cent.
As we have already stated, the average percentage of chlorides found
in the blood serum of the native of Bengal varies within narrow
limits in health and is usually from 0.72 per cent. to 0.75 per cent.
W e t a b u l a t e a f e w o f t h e e s t i m a t i o n s c a r r i e d o u t s h o w i n g t h e t o t a l
chlorides of the serum of the Bengali.
(1) M'Cay—The Lancet, 1st June 1907.
(2) Von Noorden—The Physiology of Metabolism, 1907.
(3) Landois—A text-book of Human Physiology, 1904.
22
Table VIII.
S e r i a l N o .
Cast e—Cl ass.
Total salt con-
centration of
serum by
hæmolysis
met hod.
Total chlorides of
serum estimated
by Harvey-
McKendrick
me t hod.
1
.
.
.
. Hindu Durwan
.
. 0.875 per cent. 0.728 per cent.
2
.
.
.
.
„ Dome
.
. 0.890 „
0.710 „
3
.
.
.
.
„ Student
.
. 0.970 „
0.770 „
4
.
.
.
.
„ Student
.
. 0.870 „
0.720 „
5
.
.
.
.
„ Dome
.
. 1 . 0 7 0 „
0.763 „
6
.
.
.
.
„ Bearer
.
1.016 „
0.754 „
7
.
.
.
.
„ Durwan
.
. 1.060 „
0.750 „
8
.
.
.
.
„ S t u d e n t
.
. 1.320 „
0.725 „
9
.
.
.
.
„ Coolie
.
. 0.928 „
0.730 „
1 0
.
.
.
.
„ Bearer
.
.
1 . 0 9 0 „
0.723 „
The average we have obtained works out at 0.735 per cent. which would be
0.18 per cent. to 0.20 per cent. of chlorides more than is present in the blood
serum of the European.
This extra amount of chlorides in the blood serum of the Bengali would
completely account for the higher total salinity of his serum, viz : 1.06 per cent.
to 1.09 per cent. compared with the total salt concentration of the serum of the
European, viz., 0.85 per cent. to 0.90 per cent.
As already mentioned, the higher salt concentration would assist in raising
the specific gravity and also, in all probability, would tend to increase the alkali-
nity of the blood. With regard to the hæmalkalimetry of the Bengali we are
not in a position to make any definite statement, but an investigation based on
the valuable methods introduced by Moore and Wilson (1) is being carried out.
The values to be obtained for the basic reactivity of the inorganic salts of
the serum to di-methyl-amido-azo-benzol should give important results in the
Bengali and opens up a wide field of research, both from a physiological and
pathological aspect.
4. The coagulability of the blood. —A series of observations was carried
out determining the time of coagulation, the method introduced by Wright being
(1) A Clinal Method of Hæmalkalimetry ; Moore and Wilson ;— Bio-Chemical Journal, 1906.
23
followed in every case. The time required for coagulation in Europeans is
usually stated to be from 4 to 6 minutes.
In the Bengali the clotting of the blood is very much quicker than in the
European: The average time of coagulation obtained in our series is from
13/4—21/4 minutes. These observations were all carried out at blood heat.
The short time required for clotting in the Bengali is well-known to all
workers on blood ; the ordinary finger-prick, from which in the European a com-
paratively large quantity of blood can be obtained, in the Bengali rapidly closes
and becomes sealed by a clot.
The cause of this rapidity of coagulation is difficult to explain. One factor
probably is the numerically high limits of the corpuscular elements and more
particularly the numerically high average of the white corpuscles in the blood
of the Bengali. Another factor which we consider of great importance is the
greater salinity of the blood found in the people of this province. The effect
of this increased salinity is in all probability to increase the degree of alkalinity
of the blood and also to increase the facility with which the blood clots. It may
be that with this increased salinity we have at the same time a higher concentra-
tion of calcium salts in the blood of the Bengali than in the European ; any
increase in the number of calcium ions present, within certain limits, will favour
coagulation just as a deficiency seems occasionally, as in hæmophilia, to be
responsible for a diminished coagulability of the blood.
5. The blood pressure in the Bengali .—In healthy adult male Europeans
the normal average pressure of the blood in the brachial artery varies from 110
to 130 mm. Hg., in the sitting posture. This pressure varies comparatively little
in health for the same individual when measured under similar circumstances and
on the same artery.
We have taken readings of the blood-pressure in the brachial artery in over
500 adult male Bengalis. The instrument used was Riva Rocci's sphygmoma-
nometer with Recklinghausen's broad armlet. The pressure was noted at the
disappearance of the pulse in the radial artery—the arm being placed on a level
with the heart. All readings were taken with the person examined in a sitting
position.
On the whole series the average blood pressure (systolic) of the Bengali
works out to be just under 100 mm. Hg., a good average systolic pressure in the
brachial artery lying between 95 and 105 mm. Hg.
The blood-pressure of Bengalis is therefore on a much lower scale than is
the case in the European — a condition that must affect their vigour and
energy. The factors in the causation of the lower type of pressure of the
Bengali are, probably, manifold. That difference in climatic conditions is not
the chief cause is shown by the fact that Europeans living in the same
24
climate do not exhibit, even in the hot, moist atmosphere of Calcutta, such a
low average blood pressure as is seen in the Bengali. As would be expected,
the vasomotor system becomes more or less accustomed to the new conditions
and regains its function of maintaining the tonicity of the vessels in the area
of peripheral resistance ; this in its turn is one of the principal factors in the
maintenance of blood-pressure. In the consideration of this question the force
and frequency of the heart-beat is a factor that cannot be neglected. In the
second part of this paper we shall have evidence to bring forward regarding the
physical development of the Bengali and his power of muscular exertion which
will tend to show that the capacity for muscular work is decidedly superior in
the European.
From a similar line of argument we hold that the same causes that effect
the superiority of the European's ordinary voluntary muscles also maintain the
muscular tissue of the heart in a higher state of nutrition and permit of the
superior force and vigour of its contraction.
Whatever the cause or causes may be, the pressure of the blood in the
arteries of Bengalis is from 15 per cent. to 22 per cent. lower than in Europeans.
It is worth recalling in connection with this that the percentage of hæmoglobin
is also only about 75 per cent. to 80 per cent. of the European standard.
To a consideration of this subject we shall return later ; at present, we
may close our investigations on the blood of the Bengali by collecting the results
in the form of a table comparing them with normal European standards.
Table IX.
No.
Headings.
European.
Bengali.
1
.
. . Red blood corpuscles
.
5,000,000
5,300,000
2
.
.
. White corpuscle
. 6000—8000
9000
3
. .
. Hæmoglobin
.
.
100 per cent.
81 per cent.
4
.
.
. Specific gravity
.
.
1054—1057
1055—1058
5
.
.
. Proteids
. .
. 19.17 per cent.
18.23 per cent.
6
.
.
. Total solids
.
. 21.13 „
20.12
„
7
.
.
. Salts .
.
.
.
. 7 8 „
1.06—1.09 „
8
.
.
. Chlorides (Serum)
.
. 5 5 „
.72—.75
„
9
.
.
. Time of coagulation
.
4—7 Mins.
1¾-2½ Mins.
1 0
.
.
. Systolic blood pressure in
brachial artery.
115—130 mm. Hg. 90—105 mm, Hg.
25
Part II. The Metabolism of the Bengali and its bearings on
Dietary Standards.
In the first part of this paper we have shown from the analyses of the urine
of a large number of different individuals comprising several classes that the
total amount of proteid metabolised on the average by the Bengali is only 37.50
grammes per day and that, therefore, only a slightly greater quantity than this
of assimilable proteid is absorbed from their ordinary diet.
On the other hand, according to Carl Voit, who is held in the very
highest estimation as a student of nutrition, an adult man of average body-
weight (70—75 kilos.) doing moderate muscular work requires 118 grammes of
proteid, of which 105 grammes at least should be absorbable.
This is the standard perhaps most generally accepted amongst Europeans
as covering all the nitrogenous requirements of the body ; it will be evident, if
our results as stated above are correct, that the people of Bengal live and
prosper on a diet that contains about one-third of the amount of proteid consi-
dered by Voit absolutely necessary.
Before proceeding to a detailed examination of the bearing of the meta-
bolism of the Bengali on diets, we shall very briefly review the different theories
that have been propounded to explain the rôle of the nitrogenous materials of
the food in the general economy of nutrition. The discussion hinges on the
nature of the material used up in connection with muscle work ; on the answer
to this will depend, in a large measure, the kind of food-stuff that should be
taken in to supply the part used up. Chittendee(1) makes a clear statement of
the point at issue in these words : " If the energy of mechanical work, the
energy of muscular contraction, comes from the breaking-down of proteid
matter alone, then obviously excessive muscular work would need to be accom-
panied, or followed by a generous supply of proteid food. If, on the other hand,
external work means liberation of energy solely from non-nitrogenous materials,
then it is equally clear that fats and carbohydrates are the proper foods to offset
the drain incidental to vigorous muscular action."
The view advanced by Liebig and modified later by Pflüger was the
dominant one for years. According to this theory the products of the digestion
of proteid food-stuffs are built up into the protoplasmic molecules of the living
cells, and there, in a readily oxidisable form, are available for the supply of
energy ; further, that proteid material alone is the one and only source of the
energy of muscular contraction. Liebig's view, if true, should entail a great
increase in the output of nitrogenous waste-products on the liberation of muscle
energy ; but, from faultless experiments, such was not found to be the case;
variation in the amount of work performed is practically without influence
(1) Chittenden. The Nutrition of Man, 1907.
26
on the excretion of nitrogen. On the other hand, increased muscular exertion
does entail a marked increase. in the consumption of oxygen and in the excretion
of carbon dioxide. Non-nitrogenous matter had, therefore, to be considered as a
source or as the main source of the energy of muscular contraction.
To-day an hypothesi s(1) al most di ametri cal l y the opposi te of the theori es of
Liebig and Pflüger is held in much favour. According to this view the
nitrogen of the proteid food-stuffs is rapidly eliminated from the products of
digestion, and excreted in the form of urea, whilst the carbohydrate moiety of
the proteid molecule forms, on oxidation, the main source of the energy-
supply of the organism. The tissues themselves undergo degradation under
exceptional circumstances only, as, for example, when the supply of food is
insufficient to produce the energy required by the body. According to those
who hold. this view, as the main source of energy is the oxidation of the non-
nitrogenous part of the proteid molecule,(2) nitrogenous food should play a com-
paratively subordinate role in the general economy of nutrition, and its function
.as a source of energy should be capable of being entirely replaced by carbohy-
-drates and fats.
The researches of Chittenden, Siven and others have all been directed to
the establishment of this conception ; Chittenden's works in particular being
an earnest plea for moderation in the proteid intake. This view clearly
recognises the all-importance of nitrogenous food in the nutrition of the body.
It is the only source of nitrogen available in the system and the only source from
which the proteid-containing tissues of the body can be maintained. It is, there-
fore, obvious that " there must be a certain amount of true proteid tissue broken
down each day, independent of that larger metabolism coincident with the intake
of proteid food." We have therefore to distinguish between two forms of
metabolism—the metabolism of energy and the metabolism of tissue—which are
quite distinct from each other. The tissue changes should be fairly constant
under ordinary conditions for any given individual ; the one factor determining
their extent being the weight of the true tissue elements of the body.
In connection with this view Folin(3) has recently made a further advance in
our knowledge. He has shown that the change from a nitrogen-rich to a
nitrogen-poor diet is followed by significant changes in the composition of the
urine. As would be expected, the output of urea diminishes in amount, but,
more important than this, it diminishes relatively in comparison with the other
nitrogenous constituents. On the other hand the kreatinin and sulphur output
remains constant, whether the diet be highly nitrogenous or not.
(1) Speck. Ascher and Spiro's Ergeb. der Physiol. Bio-Chem., 1903.
(2)Schryver ; Bio-chemical. Journal, 1906.
( 3 ) F o l i n ; Ame r i c a n J o u r n a l o f P h y s i o l o g y , 1 9 0 5 .
2 7
Folin therefore concludes that metabolism may be considered under two
heads, viz.: —an endogenous metabolism due to the constant tissue changes
above referred to, which is responsible for the kreatinin and sulphur (neutral)
of the urine, and exogenous metabolism, varying directly with the proteid intake
and which is responsible for the greater part of the urea of the urine. Accord-
ing to this view the only nitrogenous matter necessary for the up-keep of the
nitrogenous tissues of the body is the amount necessary to supply the waste
represented by the endogenous metabolism, and which is excreted in the form
of kreatinin.
There are, therefore, widely divergent views held with regard to the role of
the nitrogen of the food ; on the one hand we have the theory that all the
absorbed proteids are built up into the living protoplasm of the tissues and that
large amounts are necessary to maintain the organism in full bodily vigour ; on
the other hand we have the view held by Folin and others that only those
quantities are necessary that are required for the repair of tissue waste, and that
it is from the non-nitrogenous constituents of the food that the source of mus-
cular energy is obtained.
It is generally admitted that the energy of muscular contraction cart come
from all three classes of organic food-stuffs, but, so long as non-nitrogenous
food is supplied in adequate quantity or is stored up in the tissues, muscular
energy is derived principally from that source. When it is gone, proteids are
attacked, vigorous work being then attended with increased nitrogenous waste.
The evidence in favour of this view is overwhelming and it may be accepted as
a sound working basis.
The question is, therefore, narrowed down to this :
—
Accepting the view that the energy of muscular contraction can be, and
is normally supplied by non-nitrogenous food-stuffs, are we, therefore, justified.
in advocating a large decrease in the proteid intake from Voit's standard?
Is the amount of proteid necessary for the repair of true tissue waste—
Folin's endogenous metabolism—and that necessary to cover the loss from
external secretions, hairs, epithelial scales, etc., all that is required by the
system ? If so, then a few grammes of proteid a day is all that is absolutely
essential.
In other words, are we justified in stating that a diet should contain only
the minimum amount of proteid on which nitrogenous equilibrium can be main-
tained? If we are not justified in this belief and admit that an extra quantity of
proteid above the minimum necessary for nitrogenous equilibrium is for the
welfare of the body, then where is the line to be drawn? The question at once
arises, if a small extra amount of proteid beyond actual requirements is for the
advantage of the proteid-containing tissues, will a larger quantity not be to their
E2