TRANSACTIONS OF SECTION I. 975 
A variety of microbes were used, including B. pyocyancus, B. anthracis, 
B. murisepticus, and hay infusion. These were used in various degrees of virulence, 
but whether the rapidly fatal form or that which was more attenuated was 
inoculated, in no case did the effects include a rise in temperature. In three of the 
mice the respiratory exchange, and in five others the respiratory and nitrogenous 
exchanges, were observed. The temperature of the mouse varies from 35° C. to 
39-2° C., and the average of seventy observations on normal mice, living in ordinary 
conditions, was 37°6° C. The highest temperature we obtained in inoculated mice 
was 40° C., and this we observed only once. 
’ The variations in respiratory exchange were never so great as to be compared 
with those which can be obtained by giving food, or especially those due to vary- 
ing the temperature of the surrounding air. As regards nitrogen it is possible in 
the case of mice to approximate very closely to balance in the normal condition. 
In the case of infected mice there was never obtained any increase in the excretion 
of nitrogen sufficient to warrant us in inferring that the metabolism had been 
disturbed. 
The food supplied to the mice was dog biscuit, and with this the amount of 
nitrogen consumed per kilo was somewhere about twenty times as great as that 
taken by man per kilo (19°58 per kilo being the average). 
This result is important, inasmuch as the gaseous exchange in the two cases 
shows an almost similar ratio. Since the demands for heat production in the 
economy of the mouse must be enormously greater than those in man this result 
throws some doubt on any attempt to regard the oxidation of carbon, &c., as 
exclusively concerned in heat production. 
The conclusion involves the severance between fever and the infectious process 
in some of the most susceptible animals, and indicates anew the necessity of study- 
ing the occurrence of this condition in the separate species. 
2. The Physiological Effects of ‘ Peptone’ when Injected into the Circulation. 
By Professor W. H. Tuompson, I.D., Queen’s College, Belfast. 
This communication dealt with two of the effects of Witte’s ‘ peptone ’ when 
introduced into the system of the dog by intravenous injection, viz. (1) Its 
influence on the rapidity of blood coagulation, and (2) the manner in which this 
substance brings about its well known vascular dilatation. 
The animals were anesthetised in the first place by a hypodermic injection 
of morphine and atropine, and subsequently, when necessary, by chloroform or a 
mixture of chloroform and ether. Curare was administered in certain cases, 
A solution of Witte’s ‘peptone’ in 0°7 per cent. sodium chloride was then 
rapidly injected into the femoral vein, blood-pressure being recorded from the 
carotid artery. 
The results obtained were :— 
1. That Witte’s peptone in doses below two centigrammes per kilo hastens 
blood-coagulation, while in larger doses retardation of this process is caused, as 
other observers have found. 
2. That this substance produces a fall of blood-pressure in doses as low as 
fifteen or even ten milligrammes per kilo. Differences between these results and 
those of others, in regard to the magnitude of the dose, probably depend on differ- 
ences in the rate of injection employed. When slowly injected considerable 
quantities may be introduced without affecting blood-pressure. 
5. That the fall of blood-pressure produced by this substance is due to a 
peripheral dilating influence on the blood-vessels. No ‘central’ influence has so 
far been proved. 
4. That the vascular dilatation is not confined to the splanchnic area, but 
extends to other blood-vessels as well. 
5. Thatethe peripheral dilating influence is brought about by depressing the 
irritability of the neuro-muscular apparatus of the blood-vessels, rendering it 
‘irresponsive to vaso-constricting impulses, 
