NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
8
sweat, milk, hairs, epithelial scales, intestinal secretions, etc., is so small that it
may be neglected.
As nitrogen forms on an average about 16 per cent. of the proteid molecule,
we are able to calculate from an estimation of the total nitrogen the amount of
proteid material broken down in the body, one gramme of nitrogen in the urine
requiring the katabolism of 6.25 grammes of proteid.
Further, since the human system is ever striving after a condition of nitrogen-
ous equilibrium—so long at least as the weight of flesh is constant—we have, in
this total nitrogen determination, a measure of the total proteid intake of the
food. That such is the case is shown by the effect of a pure proteid diet on the
output of nitrogen, every increase in the proteid of the diet resulting in a corre-
sponding increase in the excretion of nitrogen.
„ The hungry or fasting man with his income entirely cut off, and conse-
quently suffering from a heavy drain upon his capital stock, would be expected
when suddenly supplied with fresh capital in the form of meat or other kind of
proteid food, to hold on firmly to this important kind o f food-stuff ; but such
is not the case.
" It is impossible, for example, to establish nitrogenous equilibrium by
an income of proteid equal to what the individual during fasting is found to
metabolise".(1)
The rise in proteid metabolism on an increase in proteid intake occurs to
such an extent that the system is generally able to maintain itself in nitrogenous
equilibrium on the most diverse amounts of proteid food. From this it must
follow that the body is unable to store any excessive quantity of proteid except
by the formation of muscle. (2)
In an average-sized man the total daily excretion of nitrogen, according to the
generally accepted urinary standards for Europeans, varies between 14 and 18
grammes. This would correspond to from 88 to 112 grammes proteid katabol-
ism in the 24 hours. It would also mean, if nitrogenous equil brium were being
maintained, that an equal quantity of assimilable proteid food would be required.
(Slightly more than this is necessary to cover the loss of nitrogen in other ex-
cretions and secretions, but the amount is trifling and may be neglected.)
Now, let us examine how the nitrogen elimination in the urine of Europeans
compares with the results obtained from the urine of the Bengali.
From the averages of four or five analyses on consecutive days—Table I—
we find that the minimum average of nitrogen excreted is 3.40 grammes, the
maximum being 9.04 grammes and the average for 124 observations on students
working out at 6.05 grammes.
(1) Chittenden—The Nutrition of Man, 1907.
(2) Cf. Von Noorden—The Physiology of Metabolism, 1907.
9
The minimum average for durwans will be seen to be 2.61 grammes ;
the maximum 9.3o grammes ; the average amount of nitrogen eliminated on
36 daily analyses being 5.94 grammes. In the case of bearers, domes and
mehtars similar figures were obtained, the average on 40 daily observations
being 5.96 grammes.
The average of nitrogen excretion over the whole series of 200 analyses
comes to the small amount 5.98 grammes daily. This very small total
nitrogen excretion in the urine of the Bengali is in marked contrast to the 15 to
18 grammes excreted by Europeans and, from a scientific point of view, forms
one of the features of the results. It means the metabolism of only about
37.5o grammes of proteid daily by the Bengali—a minimum below that obtained
by Chittenden in his different experiments.
Even the average for five consecutive days in the case of the student who
gave the highest results only comes to 56.5o grammes of proteid material meta-
bolised per day ; the minimum being so low as 21.25 grammes.
Chittenden was able after some months' training to maintain himself in nitro-
genous equilibrium on 37—40 grammes proteid daily ; but, as Von Noorden
states, " All these experiments (Chittenden's) have to be examined from another
point of view—namely, from that of the individual who has to maintain himself
in nitrogenous equilibrium on this daily dietary and for a long period."(1)
In the present observations we are dealing with individuals who had a per-
fectly free choice of food and whose several conditions in life corresponded in
every way to the great majority of the population of the country. We have,
therefore, ideal conditions in which the lower limits of proteid metabolism is
constantly present for an enquiry into the much discussed metabolic problem of
the present day—the quantity of proteid in an ideal diet. To this we shall
return in the second part of this paper. In the meantime it will suffice to point
out that the total nitrogen in the urine being a measure of the proteid katabolism
is also a measure of the nitrogenous material assimilated from the diet ; so that
we can calculate—with a fair degree of accuracy—the total proteid value of the
food of the different individuals and classes examined during the period they
were under observation.
This value works out, on the average, to be about 37.5o grammes
of assimilable, proteid intake in the 24 hours. Chittenden's different groups
were allowed quantities varying from 56, 63 to 67 grammes proteid daily, and
on these they maintained a condition of nitrogenous equilibrium for many
months.
The figure 37.5o grammes represents only about 32 per cent. of Voit's
standard. [Voit's diet contains 11 8 grammes proteid.]
(1) Von Noorden.—The Physiology of Metabolism.
10
5. The freezing-point of the urine.—So far as our observations go on the
freezing-point of the urine of the Bengali—and we have made some hundreds
besides those recorded on Table I—they would appear to show that the
depression of the freezing-point varies directly with the specific gravity in normal
urine and nothing of much importance can he learned by its determination that
is not equally well shown by taking the specific gravity accurately. This
subject has already been dealt with in another paper. ( 1 )
As would be expected from the lower specific gravity and lower total
quantity of solids, the urine of the Bengali causes less depression of the freezing-
point than is the case in Europeans.
The average freezing-point of the urine for students is—1.52° C; for
durwans and bearers-1.35° C, and for domes and mehtars—1.01° C ; on the
whole series the average obtained was—1.24° C.
The variations met with are very great—ranging between—0.68º C and
—2.45° C. In Europeans the freezing-point is usually—2° C to—2.6° C.
With regard to the question of the value of the determination of the
freezing-point as a means of measuring the work done by the kidney we cannot
agree with the view that the quantity of urine passed multiplied by the difference
in the freezing-points of the urine and blood—the formula Q ( Δ —D)—is any
index of the work of the kidney in excretion.
We have many observations in which the freezing-point of the urine was
actually less depressed than that of the blood, which would mean that the work
of the kidney was a negative quantity ; and yet a large quantity of dilute urine
containing quantitatively the normal amount of solids was being voided. For
further information on this point we would refer to Hill and Moore's work on
the subject.(2)
6. The Chlorides.—An examination of the quantity of chlorides was made
in every instance, as it was expected the percentage and total quantity present
would be high on account of the largely vegetable character of the diet. In
Europeans the average quantity excreted per day is about 15 grammes, varying
directly with the amount ingested with the food.
The variations in the amount excreted met with in Bengalis will be seen
from Table I to be from 4.35 grammes to a maximum of 19 .30 grammes on
the average figures of four or five consecutive daily analyses.
The average excretion of chlorides over the whole series of analyses is
9.43 grammes daily,—a quantity considerably lower than the average for
Europeans.
(1) McCay.—The Lancet, 1st June 1907.
(2) Hill.—Recent Advances in Physiology and Bio-Chemistry, 1907.
This is the more remarkable when the almost entirely vegetable nature of
the diet is considered. Bunge (1) has called attention to the fact that among men
and animals the craving for salt is limited, for the most part at least, to those
living on vegetable food. On a purely animal diet there is no desire for salt.
Bunge explains this phenomenon in the following manner. Most vegetable foods
contain a large quantity of potassium and these salts on absorption react in the
blood with sodium chloride, giving rise to potassium chloride and potassium
sulphate ; both these salts are removed at once by the kidneys since they are
both practically foreign to the blood ; so that the blood in this way loses some of
its sodium chloride ; hence the craving for more salt with vegetable food.
We were therefore prepared to find a high average in the salt excretion of
the Bengali as he had a free choice in the quantity of salt taken with his vege-
table food. But such is not the case ; the quantity got rid of by the kidneys is
actually lower than in Europeans.
These results are in striking contrast to those shown in Table XIII, where the
intake and output of salt is very excessive. This, however, is a subject to
which we shall return when dealing with the metabolism of the Bengali.
The quotient Δ/Na Cl% (Δ= freezing-point of urine) representing the ratio of
the total concentration to the sodium chloride concentration varies relatively
in Europeans, within narrow limits—diet, according to Von Koranyi, having no
fluence.
As has already been shown,(3) the limits of variation met with in the
Bengali are very much wider, being in the above series from .72 to 1.80, com-
pared with variations in Europeans lying between 1.23 and 1.69. The quotient
Δ /
N a C l %
in the Bengali nearly approaches unity.
The second table—Table II—gives the results of observations on some of
the other constituents of the urine not mentioned in Table I. These include
uric acid, phosphates, sulphates, and in a few cases the organic sulphates.
Although the number of these analyses may be considered too limited they serve
to give some indication of what the standards under these headings of the
urine of Bengalis work out to be.
As already stated, investigations having for their object the further study of
the different forms of nitrogenous waste products other than urea are at present
being carried out. These will include in addition to urea
(a) The ammonia nitrogen—that is, the nitrogen found in the form of
ammonia salts which liberate free ammonia on the addition of a
fixed alkali.
(1) Bunge.—Physiologie des Menschen, Vol. II, 1901.
(2) McCay.—The Lancet, June 1907.
C 2
(b) The kreatinin nitrogen—that is, the amount excreted as kreatinin
indicative of a special form of metabolism. According to Folin this
nitrogen is probably a measure of the constant variety, which he
calls endogenous or tissue metabolism.1
(c) The purin-bodies nitrogen (including uric acid, xanthin, hypo-
xanthin)—these probably also indicate a special form of metabolism.
7. The Phosphates.—The average amount of phosphoric acid in combi-
nation with lime magnesia and alkali excreted by Europeans is usually said to
be from 2—3.5 grammes daily, and its relation to the excretion of nitrogen is
as 5 or 6 : 1. The average in Bengalis from the analyses shown on Table II is
0.918 grammes in the 24 hours. This is little more than one-third of the
amount got rid of by the European, but, as will be seen, its relation to the nitrogen
in the urine of the Bengali works out to practically the same as in the European.
The phosphoric acid in the urine is largely determined by the nature and
quantity of the food ; it is not, however, furnished by ordinary proteids, but by
tissues rich in nuclein.
The "flesh" of the body contains nitrogen and phosphoric acid in certain
proportions. If "flesh" be put on, phosphoric acid is retained ; when the
muscles waste, proteid is lost and phosphoric acid is also lost from the body ;
the loss of proteid and phosphoric acid is in the proportion in which they are
present in muscle.
In human muscular tissue the relation between nitrogen and phosphoric acid
is N/P2O5=100/13.7—7.3 (Von Noorden).
Table II.
No.
No. of ob-
nervations
(average).
Total
quantity in
c.
c.
Phosphates
grms.
Uric Ac.
grms.
Total
Sulphates
grms.
Organic
Sulphates
grms.
1 .
. .
.
.
.
3
1063
.970
.552
1.62
2
.
.
.
. .
.
2
1530
1.462
.535
1.65
3
.
.
. .
.
.
2
1215
1.012
.631
1.69
4
.
.
. .
.
.
3
1113
.927
.467
1.50
.148
5
.
.
. .
.
.
2
1210
.859
.363
1.816
.142
6 .
.
. .
. .
2
625
.735
.388
2.78
. 1 9 1
7
.
.
.
.
. .
4
1324
.781
.536
1.30
.143
(1) Otto Folin.—Laws governing the Chemical Composition of Urine. A Theory of Proteid Metabol-
sm. American Journ. of Physiology, Vol. XIII.
13
Table II—continued.
No.
No. of ob-
servations
(average).
Total
quantity in
c. c.
Phosphates
grms.
Uric Ac.
grms.
Total
Sulphates
grms.
Organic
Sulphates
grms.
8 . . . .
. .
2
1190
.967
.410
1.30
9
. . . .
. .
2
845
.886
.531
1.94
1 0
. . . .
. .
2
965
.852
.315
1.94
1 1
. . . .
. .
2
756
.835
.333
1.852
1 2 . . . .
. .
3
1 1 1 0
.734
.364
2.110
8. The uric acid. —Healthy Europeans excrete from .3 to .75 grammes of
u r i c a c i d d a i l y ; i f l a r g e q u a n t i t i e s o f a n i ma l f o o d r i c h i n p u r i n - b o d i e s , s u c h a s
thymus or sweet-bread, are taken, the daily output may be increased up to
1.5—2 grammes.
It does not arise from the disintegration of simple albuminous bodies but
is chiefly derived from the nucleins of the food.
The excretion of uric acid, on a diet free as possible from purin bodies, is
fairly constant for each individual; it arises from the nuclein bodies of the tissues
and has been called endogenous in contradistinction to the exogenous uric acid
originating in the nucleins of the food. ( 1 )
The present investigations on the uric acid output of the Bengali give an
average excretion of 0.452 grammes daily, which is about the same as that of
Europeans on a purin-free vegetable diet. The " dhall " (pulse) in the food of
the Bengali contains a high percentage of purin bodies (Walker Hall), so that
the total quantity of uric acid excreted covers that derived from the " dhall "
and that due to endogenous metabolism ; this latter amount in the Bengali must
be very small. It will be of interest to obtain the excretion of this endogenous
uric acid in the Bengali (by giving a purin-free diet) and compare its amount
with the results obtained in Europeans.
9.T h e S u l p h a t e s .
— N e a r l y t h e w h o l e o f t h e s u l p h u r t a k e n i n t h e f o o d
reappears in the urine ; when completely oxidised it occurs as free or combined
sulphuric acid, and in organic combinations as neutral or organic sulphur. The
total sulphuric acid excretion under ordinary nutritional conditions in Europeans
is from 1.5—3 grammes daily ; and the quantity of combined sulphuric acid in
a healthy European on an average diet is from 0.12—0.25 grammes a day.
In Bengalis the analyses would show, on the whole, a diminution in the
(1) Folin.—American Journ. of Physiology, Vol. XIII.
14.
total elimination of sulphates compared with Europeans. The average works
out at 1.88 grammes.
The combined sulphuric acid occurring in the urine as aromatic products—
such as indol, skatol, etc.—from the few analyses carried out averages 0.156
grammes a day.
The quotient ethereal sulphuric acid over the total sulphuric acid in
Europeans is usually 1/10 to 1/12 ; this relationship holds good also, so far as our
observations go, for the Bengali.
The old view that this quotient gave a measure of the amount of intestinal
putrefaction has now been given up ; the denominator of this fraction, the total
sulphuric acid, depends on the total amount of albumen consumed and has
therefore no connection with putrefaction. ( 1 )
This finishes the observations on the standards of urinary constituents in
the Bengali. It would make for clearness, perhaps, if they are compared in the
form of a table with those found in Europeans.
Table III.
Constituents.
In European.
In Bengali.
Quantity .
.
.
.
.
.
1440 c.cs.
1200 c.cs.
Specific Gravity .
.
.
.
.
1020
1013
Urea (Grammes)
.
.
.
.
35
13
Total Nitrogen (Grammes) .
.
.
18
6
Freezing-point .
.
.
.
.
—2.5° C.
—1.24° C.
Chlorides (Grammes) .
.
.
.
15
10
Phosphates (Grammes)
.
.
.
3.5
0.918
Uric Acid (Grammes) .
.
.
.
0 . 75
0.452
Sulphates (Grammes) .
.
.
.
2.5
1.880
B. THE BLOOD.
The very marked differences met with in the urine of the Bengali would
a priori lead us to suspect something of a similar nature also in the blood
compared with its composition in the European. The usual well-recognised
(1) Von Noorden.—The Physiology of Metabolism, 1907.
15
methods of blood examination have been made use of, and newer methods
employed and modified to push the examination as far as possible in order to
obtain a knowledge of any departure from European standards.
The result of the urine analyses has been shown to be that the percentage
or total quantity of the constituents excreted was on a very much lower scale
than is the case in Europeans ; the blood being the source from which the urine
is derived, we should expect to find some modification in its chemical compo-
sition and formed elements.
Let us examine the evidence at our disposal.
1. The corpuscular enumeration and hæmoglobin value. —The ordinary
routine examination—enumeration of the red and white corpuscles and the
estimation of the percentage of hæmoglobin—was carried out in 170 different
persons ; about two-thirds of these were students, the remaining third was
composed of many different classes. All the individuals taken into account
were in good health and were, as far as could be judged, typical of the blood
condition of the Bengali.
As there is nothing to be gained by giving the individual analyses in full
detail, we publish in Table IV the averages of the different constituents for stated
percentages of hæmoglobin.
Table IV.
No.
No. of
observa-
tions.
Average
percent-
age of
hæ mo-
globin.
Average
of
R. B. C.
Average
of
W. B. C.
Class.
1
9
92
5,520,000
10,400
Hb.—90 per cent. or over.
2
30
87
5,500,000
9,800
Hb.—85—90 per cent
3
60
81
5,300,000
9,700
Hb.—80—8 5 „
4
27
76
5,200,000
8,700
Hb.—75—80 „
5
20
71
4,810,000
8,000
Hb.—70—75 „
6
1 0
67
4,800,000
7,650
Hb.—65—70 „
In the remaining 14 observations the corpuscles and hæmoglobin were
below the above standards, so that the individuals could not be considered
healthy. From an examination of the above table we may conclude—
16
(a) The average number of red blood corpuscles per c.m. of blood in the
Bengali is greater than in Europeans. In over 80 per cent. of
those examined this average works out to be 5,300,000 per c.m.
In European healthy adult males the average number of red blood
corpuscles was 5,190,000 per c.m. over 113 observations. ( 1 )
(b) The white blood cells are, on the average, slightly more numerous
than in Europeans. On 156 observations the average number is
9000 per c.m.
(c) The hæmoglobin estimation (Haldane's modification of Gower's
method—the carbon monoxide method—) was followed in every
instance. The limit of error in this method of estimation is not
more than 1 per cent.
The blood of the Bengali shows a very decided deficiency in hæmoglobin
compared with the European. On the 156 observations shown on above table
the average amount of hæmoglobin was only 79 per cent. ; and over 75 per cent.
of the persons examined possessed only 81 per cent. of hæmoglobin.
When we recall that the Bengali has a greater number of red blood cells
than the European and, at the same time, shows a marked deficiency in the
percentage of hæmoglobin, it follows that the hæmoglobin value per red cell is
much below the normal European standard.
In Europeans the hæmoglobin value per red corpuscle varies normally from
0.95 to 1.1. ( 2 ) I n B e n g a l i s , o n t h e o t h e r h a n d , t h i s r a t i o i s a b o u t 0 . 7 5 ; t h i s
means, instead of each red blood corpuscle being in possession of its normal
amount of hæmoglobin, it has, on the average, only about 75 per cent. of that
quantity. It will be evident from these facts that the oxygen-carrying capacity
of the blood must be seriously affected.
2. The specific gravity of the blood. —In the Bengali the specific gravity of
the blood averages in adult males 1057. This is slightly higher than the average
for Europeans. Stewart(1) gives an average of 1054.4 on 165 observations. The
higher specific gravity of the Bengali is probably due to the greater number of
corpuscles, and, as will be seen later, to the increased salt concentration of the
blood compared with that of Europeans.
3. The chemical composition of the blood.
(a) In order to obtain sufficient blood for analysis we had resort to the
method of " pooling." A measured quantity—about 3/10 c.c.—of
blood was taken from each of a number of individuals, usually about
(1) Stewart.—Manual of Physiology, 1906.
(2) Schafer.—Text-book of Physiology.
17
15—20; the quantity thus obtained was collected in a weighed
flask.
In this way we not only got sufficient blood to carry out analyses, but
also obtained the average composition over the number of indivi-
duals whose blood was taken.
Having weighed the flask and blood, by deducting the weight of the
empty flask, we had the weight of the blood made use of.
This was examined for total nitrogen by Kjeldahl's method and the
result noted.
(b) In a similar way the blood was "pooled" into a platinum dish—
weighed before and after.
From this blood water was evaporated off in a water bath and then in
a dessicator. On weighing again we obtained the total solids
remaining, and the water evaporated.
The solid matter was incinerated in a red hot flame to get rid of all
organic material and, this being completed, the capsule was weighed
again and the inorganic salts present estimated.
In Table V we present the averages of the results thus arrived at
regarding the blood of the Bengali.
Table V.
European (Schmidt).
Bengali.
Percentage.
Percentage.
Water
.
.
.
.
.
.
.
78.87
79.88
Total Solids
.
.
.
.
.
.
21.13
20.12
Proteids
.
.
.
.
.
.
.
19.17
18.23
Salts .
.
.
.
.
.
.
.
0.78
1.06
(c) Another method of examination made use of on a fairly large scale
was the estimation of the total salt concentration of the serum
(expressed in terms of NaCl) by Wright's hæmolysis method.
This is an exceedingly simple and easily carried out means of ex-
amining the blood. A full description of the method will be found
in Wright's original papers ; (1) its application to the Bengali has
already been worked at. (2)
(1) The Lancet-2nd April 1904 and 21st October 1905.
(2) M'Cay— The Lancet, 1st June 1907.
D