ON THE COAGULATION-OF THE BLOOD Lig 
of the strongest liquor ammoniae. Here certainly the blood was in circumstances 
in which it could not lose ammonia, but where any change in its amount must 
be by way of increase, and yet I found, on opening the receptacle by snapping 
it across after a scratch with a file, that instead of remaining longer fluid than 
in a watch-glass, the blood in it, being more in contact with the glass, was always 
more quickly coagulated, while coagulation was still more rapid in the capillary 
tube, where the blood was still more exposed to the influence of the foreign 
solid—the greater proximity to the liquor ammoniae having no influence 
upon it. 
It may perhaps be argued that the drop of blood employed being a small 
drop, and this small drop having been drawn up by suction into the tube, it 
might have parted with its ammonia before it got into the tube; but then 
(and now comes the bearing of the experiment on the effect of temperature) 
I found, if I placed a similar tube filled in the same way in a vessel of snow, 
A 
eee SEE SD 
mm 
B 
Fic. 3. 
so as not to freeze it but to keep it ice-cold, the blood in it remained fluid as 
long as I chose to keep it there. Now if all the ammonia had left the blood 
before it was introduced into the tube, cold ought, according to the ammonia 
theory, to have had no effect in retarding its coagulation ; for, according to 
that theory, cold operates by retaining the ammonia. On the other hand, if 
we take the other alternative and suppose that any ammonia which the blood 
might have contained was still in these tubes, the former experiment proves 
clearly that the retention of ammonia has-no effect in producing fluidity—no 
effect in preventing coagulation ; and if the retention of ammonia has no effect 
in preventing coagulation, then cold certainly cannot prevent coagulation by 
retaining the ammonia, because, even if retained, it would not influence the 
result. In whatever way we look at them, therefore, these simple experiments 
prove conclusively that cold maintains the fluidity of the blood in some manner 
unconnected with any influence it may exert upon ammonia. 
Then, again, I varied the experiment in this way. I placed such little 
tubes of blood in baths of liquor ammoniae at different temperatures. By 
careful management, guarding against the volatilization of ammonia and con- 
sequent reduction of temperature, I succeeded in employing satisfactorily a bath 
of liquor ammoniae at 100° Fahr., the blood being in the bath within a few seconds 
