DR. A. GAMGrEE ON THE ACTION OE NITRITES ON BLOOD. 
607 
the amount of carbonic acid by absorption with potash and of oxygen by absorption with 
pyrogallic acid. The residual gas, consisting of carbonic oxide and nitrogen, was not 
further analyzed, but merely measured. 
Obs. I. 25 cub. centims. of defibrinated and well-arterialized blood of the Sheep were 
mixed with 3 cub. centims. of a solution of KN0 2 . The 3 cub. centims. contained 
0*03 grm. of pure nitrite of potassium. The blood was allowed to remain in contact 
with the nitrite for 24 hours ; at the end of that time it had acquired the characteristic 
chocolate-colour and spectrum which I have already described. 
Pure carbonic oxide was prepared by the action of pure sulphuric acid upon chemi- 
cally pure formiate of magnesium. A measured quantity of the gas was brought into the 
laboratory-tube, into which had already been introduced 20 cub. centims. of the mixture 
of blood and nitrite of potassium. 
The blood and gas were agitated together and then left in contact for 24 hours. At 
the end of that time the gas was transferred, measured, and analyzed. 
Quantity of blood used . 17*8 cub. centims. 
Carbonic oxide taken 273*4 vols. 
After 24 hours’ contact gas measured . . . . 273*0 „ 
After absorption of carbonic acid 271*5 „ 
After absorption of oxygen 270*5 ,, 
Composition in 100 parts. 
Carbonic acid 0*54 
Oxygen 0*36 
Carbonic oxide and nitrogen . . .99*10 
100*00 
Vol. of carbonic oxide before contact = 273*4 vols. = 30*45 cub. centims. at 0° andO m *76 
Yol. of carbonic acid exhaled =1*57 vol. =0*167 cub. centim. „ 
Yol. of oxygen exhaled =1*0 vol. =0*1114 cub. centim. ,, 
The mixture of blood and nitrite was examined after the completion of the experi- 
ment, and it was found that the optical characters remained unaltered. The colour was 
still brown, and the blood exhibited the spectrum of blood which has been acted upon 
with nitrites. 
In the above experiment the agitation of 20 cub. centims. of a mixture containing 
17*8 cub. centims. of blood (diluted to 20 cub. centims. with a solution of nitrite of 
potassium) with 30*45 cub. centims. of carbonic oxide gas only resulted in the evolution 
of 0*11 cub. centim. of oxygen gas — a quantity which is quite insignificant when com- 
pared to that invariably yielded by either venous or arterial blood. In so far as an 
opinion can be formed from the results of one experiment, it would then appear either 
that under the influence of nitrites the loose oxygen of blood-colouring-matter had been 
removed, or that its constitution had so altered that its oxygen was no longer capable of 
expulsion by carbonic oxide gas. 
mdccclxviii. 4 o 
