606 
DB. A. GAMGEE ON THE ACTION OF NITEITES ON BLOOD. 
In these experiments I was only able to make percentage analyses of the gases after 
contact with blood, from the impossibility to measure, by the method used, the exact 
volume of gas after the experiment. As far as they go they fully confirm the experi- 
ments which had preceded them ; as in the case of the air brought in contact with the 
normal blood mixed with distilled water, the oxygen was decidedly diminished, whilst 
in the case of that which had been in contact with the blood and nitrite, the air remained 
quite unaltered. I have performed several other experiments on exactly the same plan 
as those just described, and with precisely similar results. As, however, those which I 
have adduced are sufficient to illustrate the action of nitrites on blood, in so far as that 
action can be discovered by this mode of experimenting, I have preferred to omit givi ng 
further details, more especially as I myself attach little importance to these percentage 
analyses of air left in contact with blood 1 . 
Experiments in which Blood was acted upon by Nitrites and then treated with Carbonic Oxide. 
In the experiments now to be described I have made use of carbonic oxide as a reagent 
for the detection and expulsion of the loosely combined oxygen existing in blood. The 
plan of the experiments has generally consisted in taking defibrinated blood of the 
Sheep and agitating it with air so as effectually to arterialize it, then treating it with 
a solution of some nitrite, and bringing it in contact with carbonic oxide gas. The car- 
bonic oxide gas used was always prepared by the action of pure sulphuric acid on pure 
formiate of magnesium ; in several of the first experiments I analyzed the gas before 
bringing it in contact with blood. I invariably found that the gas which I prepared in 
this way was absolutely pure. 
As I wished in these experiments merely to find out the amount of oxygen which the 
carbonic oxide was capable of expelling from the blood, 1 confined myself to determining 
1 Since the experiments just described were performed, I have made others with the view of determining 
whether the power which the blood- colouring-matter appears to possess of ozonizing the atmospheric oxygen 
which comes in contact with it, is destroyed by the addition of nitrites. 
Alexandek Schmibt has pointed out that when a drop of diluted blood is placed upon bibulous paper which 
has been soaked in tincture of guaiacum and dried, at the edges of the drop the paper assumes a blue colour such 
as is produced by the action of ozone. I find that the reaction can be obtained with blood which has been 
fully acted upon by nitrites. In order to observe this reaction, the blood should be diluted with twenty times 
its volume of water. I may mention that all specimens of tincture of guaiacum do not give the reaction ; of 
three samples which I purchased, only one was found to render the paper sufficiently sensitiveAo show the 
reaction, although the other two possessed the colour, smell, and taste of the genuine tincture. 
It has been shown by Schonbein that when peroxide of hydrogen is added to blood, a copious evolution of 
oxygen occurs, as when the same reagent acts upon certain peroxides. 
Blood which has been acted upon by nitrites effervesces on the addition of peroxide of hydrogen, just as 
normal blood does. 
In so far, then, as we can judge by the two experiments which bear most directly on this point, we must 
conclude that nitrites do not destroy the ozonizing properties which the blood-colouring-matter appears to 
possess. 
