IKFLUENCE O F TEMPERXTCRE ON T H E COAGULATION O F SOLS, AND T H E PROBLEM OF ACCLIMATISATION OF ANIMALS BY N. R . DHAR AND SATYA PRAKASH I n publications' from these laboratories we are trying to throw light on the problem of old age and acclimatisation. We have advanced the view that old age is associated with marked decrease in the catalytic activity of the body enzymes and cells. Consequently in old age there is an appreciable decrease in the metabolism of the animal body. Observations on the metabolism of human beings of different ages show that the metabolism expressed per square metre or kilogram is less in old age than in childhood or youth. Animal life is assumed to depend essentially on the activity of the cells or the enzymes. We have tried to prove that the phenomenon of ageing is common both to inorganic and organic colloids and precipitates. We2 have shown that the activity, adsorptjve power, stability, and viscosity of hydrophobe colloids, in general, decrease and electric conductivity increases with time. On the other hand, with hydrophile colloids the viscosity and the amount of hydration increases up to a limiting value, while the electric conductivity decreases on ageing. We have recently shown that colloids can be divided into two classes according to their behavior on exposure to light. Thus sols of ferric hydroxide, chromium hydroxide, zirconium hydroxide, ceric hydroxide, vanadium pentoxide, arsenious sulphide and manganese dioxide become less stable on exposure to light. On the other hand, sols of Prussian blue, cupric ferrocyanide, mastic, and gum dammar are stabilised when exposed t o light. I n this communication we are recording the results obtained on the influence of temperature on the coagulation of sols. The coagulation of several sols was investigated by placing the sol and the electrolyte in thermostats a t constant temperature. The following results were obtained:Ferric Hydroxide (Fe(0H)3) I n order to prepare ferric hydroxide sol small quantities of ammonium carbonate were added to a concentrated solution of ferric chloride, till the precipitate of ferric hydroxide redissolved. The sol was dialysed for six weeks.
TABLE I Concentration of sol = 26.745 grms. of Fe203per litre. Amount of sol taken each time = 2 C.C. Total volume = I O c.c.; Time = I hour. Electrolyte
Potassium chloride N:'5 Potassium chloride N,/IOO
Amount to coagulate In c.c a t 20°C a t 60°C 1.1
0.90
1.4
1.15
' D h a r : J. Phys. Chem., 30, 378, 480 (1926). * Z. anorg. allgem. Chem., 162, 237; 168, 209 (1927); Iiolloid-Z., 42,
120
(1927).
955
IXFLUENCE O F TEMPERATURE OK COAGULATION O F SOLS
Cupric Ferrocyanide Sol Dilute solutions of cupric sulphate and potassium ferrocyanide were mixed, potassium ferrocyanide being in slight excess and the mixture was dialysed for I O days, with occasional stirring. TABLE I1 Concentration of sol = 3.1 gm. per litre. Amount of sol taken each time = 2 C.C. (A-sol); I C.C. (A/z-so~). Total volume = I O c.c.; Time = I hour. Amount to coagulate in C.C. A sol a / z sol
Electrolyte
at 30°C.
Potassium chloride K/4 Barium chloride N/zoo Hydrochloric acid N/4
a t 60°C.
at 30'c.
at 60'c.
.o
2.4
I .25
3.5 1.9
2 .o
2.7
2.25
3.2
2
1 . 7
2.6
I .2
Prussian Blue Sol In order to prepare Prussian blue sol dilute solutions of ferric chloride and potassium chloride and potassium ferrocyanide were carefully mixed and a small quantity of ammonium oxalate was added as a peptising agent. This mixture was subject to dialysis for twelve days and a clear deep blue sol of Prussian blue was obtained.
TABLE 111 Concentration of the sol = 9.33 gms. per litre. Amount of sol taken each time = I C.C. (A-sol); 0.5 C.C.(A/n-sol). Total volume = I O c.c.; Time = I hour. Electrolyte
Potassium chloride N / i 4 Barium chloride N/200 Hydrochloric acid N/4
Amount to coagulate in C.C. A sol. A/s sol. at 30T. a t 60°C. a t 30°C. a t 60°C. 2.45 2.3
2.95
-
__
2
.o
3.1 I .9
3.5 I .8;
2.1
0.4
Vanadium Pentoxide The sol was prepared by taking finely powdered ammonium vanadate in a mortar, to which a concentrated solution of hydrochloric acid was added slowly till no more of red vanadic acid precipitated. The precipitate was allowed to settle and the clear liquid was decanted. The precipitate was washed three or four times by decantation with distilled water in order to free it from ammonium chloride. At this stage, the precipitate has a tendency t o pass into the colloidal state. The precipitate was now vigorously shaken in a coloured glass bottle with distilled water and a clear, deep-red coloured so1 of vanadium pentoxide was obtained.
N. R. DHAR AND SATYA PRAKABH
956
TABLE IV Concentration of the sol = 3.64 grms. V Z Oper ~ litre. Amount of sol taken each time = I C.C. (A-sol); 0.5 C.C. (A/z-sol). Total volume = I O c.c.; Time = I hour. Amount to coagulate in
A sol
Electrolyte a t 30'
Potassium chloride X/IO Barium chloride N/soo Aluminium nitrate N/zooo
c.
a / z sol. a t 30°C. at 60°C.
a t 60°C.
0.75 0.95 0.95
0.95 1.35 1.3
C.C.
0.8
0.65
I . I j
0.70
0.8
0.55
Stannic Hydroxide Sol
Stannic hydroxide was precipitated by the action of an excess of am monium hydroxide on stannic chloride solution. The precipitate on washing once or twice with water passes into a negatively charged, clear sol, which was purified by dialysis.
TABLE V Concentration of the sol = 6.66 grms. of SnOz per litre. Amount of sol taken each time = I C.C. Total volume = I O c.c.; Time = I hour. Amount to coagulate in C.C. a t 30°C. a t 60°C.
Electrolyte
Potassium chloride K / 4 Barium chloride N/zoo
1.4 0.85
2.4 1.1
Zirconium Hydroxide Sol (in hot)
A solution of zirconium nitrate was boiled vigorously for half an hour and was dialysed for I O days and a clear sol was obtained.
TABLE VI Concentration of the sol = 9.56 grms. of ZrOz per litre. Amount of sol taken each time = z C.C. (A-sol); I C.C. (A/2 sol). Total volume = I O c.c.; Time = I hour. Amount to coagulate in
A-sol.
Electrolyte a t 30%
Potassium chloride N / 4 Potassium sulphate N/200
.I 1.9 I
a t 60°C.
C.C.
A/2 sol. a t 30°C. a t 6o'C.
0.4 1.55
1.5
-
0.7
-
Zirconium Hydroxide Sol (in cold)
A clear aqueous solution of zirconium nitrate prepared at the ordinary temperature was dialysed for I O days and a clear sol was obtained.
957
INFLUENCE OF TEMPERATURE ON COAGULATIOS OF SOLS
TABLE VI1 Concentration of the sol = 9.42 grams. of ZrOz per litre. Amount of sol taken each time = 2 C.C. (A-sol); I C.C. (A/2 sol). Total volume = I O c.c.; Time = I hour. Amount to coagulate in
a sol
Electrolyte At 30°C.
Potassium chloride N/4 Sodium citrate 0.0032 M
a t 60°C.
1.9
0.9 I .6
2 .o
C.C.
A/2 sol. a t 30°C. a t 60°C. I .8
0.95
1.3
I .2
Aluminium Hydroxide Sol A solution of aluminium nitrate containing an excess of sodium acetate was dialysed for 2 0 days. A clear dilute sol of aluminium hydroxide was obtained.
TABLE XI11 Concentration of the sol = 1.32 grms. of A1203per litre. Amount of sol taken each time = 4 C.C. (A-sol); 2 C.C.(A/z-sol). Total volume = I O c.c.; Time = I hour. Amount to coagulate in
h - sol.
Electrolyte
a t 60°C.
a t 30°C.
Sodium citrate 0.0159 M Sodium tartrate 0.019M
0.8
0.6 0.9
0.9
C.C.
A/2 sol. a t 30°C. a t 60°C.
0.4
0.4
0.5
0.5
Chromium Hydroxide Sol
This sol was prepared by the action of ammonium carbonate on a solution of chromium-tri-chloride, till the precipitate of chromium hydroxi de formed redissolved. The sol was allowed to dialyse for 17 days.
TABLE IX Concentration of the sol = 1 . 7 2 5 grms. of ( 3 2 0 3 per litre. Amount of sol taken each time = 2 C.C. (A-sol); I C.C. (A/2 sol). Total volume = I O c.c.; Time = I hour. Amount to coagulate in
A sol
Electrolyte
Potassium sulphate I i / 2 0 0 Sodium citrate 0.0032 M
C.C.
A/2 sol a t 3ooC. at 60°C.
a t 3oOC.
at 60°C.
3.7
3.4
2.6
2.1
I .2
1.1
0.75
0.65
Ceric Hydroxide Sol 2 5 grms. of ceric-ammonium nitrate were dissolved in 2 5 0 at 2 5 O C . The solution was dialysed for 6 days after filtering.
C.C.
of water
N. R . DHAR A S D SATYA PRAXASH
9.58
TABLE X Concentration of the sol = 17.65 grms. of Ce02 per litre. S'olume of the mixture = I O C.C. Amount of sol taken each time = I C.C. Time = I hour. Amount to coagulate in
Electrolyte
Potassium chloride S j 4 Potassium sulphate S j z o o
C.C.
a t 30°C.
at 60'C.
4.8
1.1
I
1.4
.4
Arsenious Sulphide Sol The sol was prepared by passing a slow current of H2S in a solution of arsenious oxide, the excess of € I I S was removed by passing hydrogen.
TABLE XI Concentration of sol = 26.73 grms. of As& per litre. Amount of sol taken each time = 2 C.C. Total volume = I O C.C. Time = I hour. Amount t o coagulate in a t 30°C. a t 60"
Electrolyte
Potassium chloride K,'4 Barium chloride N/so Sulphuric acid o 6 5 / S
C.C.
at 80°C.
2 6
2.6
8.2
I.2
I .I
I .os
1
0.9 1.35
05
Sheep Serum Fresh sheep-blood was taken in a bottle in which it formed a firm clot within a few minutes. After a short time, syneresis took place and straw coloured clear serum was squeezed out, which was used for the experiments. 6 C.C. of serum on heating on a water bath for 2 hours left a residue of 3.4 grms.
TABLE XI1 Amount of serum taken each time = Volume = I O c.c.; Time = I hour. Electrolyte
Hydrochloric acid N / I O O Sulphuric acid Oxalic acid N/IOO Acetic acid N/so Potassium fluoride 8N Sodium tartrate I .91M
2
C.C.
Amount to coagulate in at 30T.
C.C.
a t 60°C
3.55 2.80
3.3 1.9 I
.85
7.15
Dammar Resin Sol A concentrated solution of dammar resin was prepared in alcohol. The alcoholic solution was poured into distilled water, and the sol thus obtained was dialysed for seven days.
I S F L C E S C E O F TEMPERATURE ON COAGULATIOS O F SOLS
959
TABLE XI11 Concentration of the sol = 4.44 grms. per litre. Amount of sol taken each time = I C.C. Total volume = j c.c.; Time = I hour. Electrolyte
Potassium chloride SjS Barium chloride N/8 Hydrochloric acid
Amount to coagulate in At 30°C. at 60°C. 1.1
0 I
55 .7
C.C.
at 70°C.
1 3
0.65
I 5
-
r*
0.55
0.8
Gamboge Sol A concentrated alcoholic solution of gamboge was poured into distilled water, and the sol thus obtained was dialysed for a week. TABLE XIF' Concentration of the sol = 7.92 grams. per litre. Amount of sol taken each time = I C.C. Total volume = I O c.c.; Time = I hour. Electrolyte
Potassium chloride N Barium chloride N/8 Hydrochloric acid N / I O O Tartaric acid N / I O Oxalic acid N / I O
Amount to coagulate in At 30°C. at 40OC.
C.C.
a t jo"C.
4.2
4.30
4.45
I .o
I .20
3.1
3.05 -
I .30 2.9 3.4
3.6 1.3
1.15
Mastic Sol .4concentrated alcoholic solution of mastic was prepared and poured into distilled water. The sol thus obtained was dialysed for a week.
TABLE XV Electrolyte
Potassium chloride PIT Barium chloride E / 4 Hydrochloric acid N/roo
Amount to coagulate in a t 30°C.
C.C.
a t j0"C.
0.75
I .4 0.9
I 2
0.95
I .2
The foregoing experimental results show that sols of ferric hydroxide, stannic hydroxide, zirconium hydroxide, (prepared in the hot and cold conditions), aluminium hydroxide, chromium hydroxide, cerium hydroxide, and cupric ferrocyanide require smaller quantities of electrolytes when coagulated at higher temperatures than a t 30'. I n other words, the above sols become more aged and unstable when kept a t higher temperatures. On the other hand, gamboge, gum dammar, mastic, and sheep serum become more stable against coagula a t higher temperatures.
960
N. R. DHAR AND SATYA PRAKASH
We have shown that sols of ferric hydroxide, chromium hydroxide, aluminium hydroxide, stannic hydroxide, zirconium hydroxide, and cerium hydroxide become less stable towards electrolytes even when kept a t the ordinary temperature, hence our experimental results show that as far as these sols are concerned the influence of temperature leads to the accentuation of the time effect. These sols become unstable more readily when kept at a higher temperature than at the ordinary. We1 have definitely shown that sols of mastic, gum dammar, gamboge, sheep serum, etc. are hydrolysed and the stability of these sols towards electrolytes increases with the degree of hydrolysis, At higher temperatures these sols become more hydrolysed and their stability is also increased at higher temperatures. In presence of acids the hydrolysis of these sols is greatly suppressed and the stability is decreased, hence in the coagulation of these sols by acids a t higher temperatures, small quantities of acids are required. In the case of Prussian blue, the sol becomes more stable towards potassium chloride a t higher temperatures, whilst it becomes less stable towards barium chloride and hydrochloric acid, It appears that cupric ferrocyanide becomes decomposed a t higher temperatures and requires smaller qnantities of electrolytes for coagulation. In a previous communication* we have applied Stefan’s law of radiation in explaining the increase in metabolism observed when the surrounding temperature of a warm-blooded animal is lowered. We have advanced the view that the effect of transportation of a warm-blooded animal from a comparatively warmer climate to a very cold climate will be to activate the enzymes and cells in the body and it will lead to the shortening of the life of the animal. On the other hand, the transportation of a warm-blooded animal from a very cold climate to a comparatively warm country is to cause the body cells and enzymes to work at a slower speed and the life of the animal may be prolonged by this transportation. It is well known that cold-blooded animals live much longer than warmblooded animals of the same size because the catalytic activity of the cells and the enzymes present in cold-blooded animals is not as great as those in warm-blooded animals. When a cold-blooded animal living in a warm country is taken to a cold country the metabolism will decrease and the animal leads a life of less intensity and greater duration. On the other hand, by the transportation of a cold-blooded animal from a cold to a warm country, the catalytic activity of the cells and enzymes is increased. This leads to a shortening of the life period of the animal. From our experiments on the coagulation of sols it will be observed that the stability of several colloids decreases considerably by increasing the temperature of the colloid, and the colloids will age more rapidly. ConseJ. Phys. Chem., 30, 830 (1926);Kolloid-Z., 39,346 (1926). J. Phys. Chem., 30, 480 (1926).
INFLUENCE OF TEMPERATURE ON COAGULATION OF SOLS
961
quently the colloids present in cold-blooded animals will have longer duration of healthy life, and this leads to the greater longevity of the animals themselves. The body temperature of warm-blooded animals is normally much higher than the surrounding air. I n the case of some birds, sparrow, hen, etc., the body temperature is about 42', in the case of rabbit 39.6' and in the case of a dog it is 39.2'. It will be clear from the results published in the foregoing pages that several body colloids cells and enzymes present in these animals will age readily and become unstable a t these moderately high temperatures. Moreover these cells and catalysts are made to work a t a high speed in order to make up for the heat lost by radiation and other sources. Consequently the longevity of these warm-blooded animals cannot be as high as that of cold-blooded animals. Voit gives the following results on the influence of temperature on the metabolism of a fasting man. Temp :COZexcreted in grms.
4.4' 210.7
6.5' 206.0
9'
14.3'
16.2'
24.2'
26.2O 30'
192.0 1 5 5 . 1 1 5 8 . 3 166.j 160.0 170.6
It appears from the above result,s that when the outside temperature is about 15' the metabolism of the animal body is the minimum. Similar results showing that the met,abolism is minimum when the external temperature is about 15' have been obtained wit'h other warm-blooded animals. We are of the opinion that t'he longevity of an animal is increased if the body cells and enzymes are made to work at a minimum speed. Moreover at the temperature I jo the body colloids do not age rapidly, hence this temperature is the most suitable one for the healthy life of warm-blooded animals which maintain a higher body temperature than the surrounding air. People living in a country under suitable hygienic conditions should have the maximum longevity, if the average temperature is near about 15'.
Summnrv Sols of ferric hydroxide, chromic hydroxide, vanadium pentoxide, aluminium hydroxide, stannic hydroxide, zirconium hydroxide, ceric hydroxide and cupric ferrocyanide require smaller quantities of electrolytes when coagulated a t 60' than the amounts required for coagulation a t 30'. (I)
The amounts of salts required to coagulate sols of dammarresin, (2) mastic, gamboge, Prussian blue and sheep serum at 40°, soo, 60' and 70' are greater than those required at 30'. When the coagulation is effected by hydrochloric acid, the amounts of acid necessary are smaller, the higher the temperature. These results can be explained from the view-point of the hydrolysis of these sols. (3)
Increase of temperature accentuates the ageing of these sols.
962
N. R. DHAR AND SATYA PRAKASH
(4) An explanation has been advanced for the greater longevity of cold blooded animals than warm-blooded ones of the same size. ( 5 ) People living under hygienic conditions in a country having an average temperature 15' should have the maximum longevity, because when the outside temperature is about I so, the metabolism in warm-blooded animals seems minimum. Chemical Laboratory, Allahabad University, Allahabad, India. Sept. IS, 1988.
