VIVISECTION NO CRUELTY. 
687 
regards its earlier stages, and if, after a few of^^ the strings 
have been tied on, the tube be cut across, the blood which is 
in the part of the tube in the vicinity of the air, just like that 
which is in the air-tight receptacles, remains fluid in part for 
two or three hours; in short, that my precautions in ensuring 
that the receptacles should be air-tight were, in so far as they 
applied to that object, utterly unnecessary. I mention this 
partly as an illustration of the deceptions to which one is 
liable in this inquiry, and partly because the experiment thus 
modified seems to tell as clearly against the ammonia theory 
as the original one seemed to tell in favour of ito Those 
receptacles which had been formed by the application of 
ligatures before the tube was opened, afforded certainly no 
opportunity for the escape of ammonia, and yet in them the 
blood coagulated as quickly as in those which had commu¬ 
nication with the air—implying that facility for the evolution 
of ammonia does not in itself affect the process of coagulation 
at all. 
How, then, it may be asked, is the persistent fluidity of 
the blood under these circumstances to be explained ? That 
will become more obvious in the sequel than I can make it at 
present; but in the mean time I may observe that there are 
probably two explanations: one is, the coolness of the tube; 
and the other (far more important), that the blood, in slipping 
through this cylindrical tube, had had little opportunity of 
being influenced by its walls. The portion of the blood that 
first came in contact with the walls of the tube had coagulated. 
And it is to be‘observed that in these experiments I never 
found the* blood altogether fluid, even after a comparatively 
short time : there has always been a certain amount of coagu¬ 
lation, and only a certain amount of fluidity. A layer of blood 
having thus coagulated upon the internal surface of the tube, 
the fresh blood which continued to flow through it was not 
brought into contact with the walls of the tube at all, but 
with their lining of coagulated blood. 
(To he continued^ 
VIVISECTION NO CRUELTY. 
The discussions at the various sections in connection with 
the late meeting cf the British Association at Newcastle 
were exceedingly well attended, notwithstanding the unpro- 
pitious weather. In the section of physiology Professor 
Rolleston presided, and opened its proceedings in an address, 
the greater part of which wa,s occupied by a review’ of the 
