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2. Some Observations on the Coagulation of the Blood. Bj 
John Davy, M.D., F.R.S. Lond. and Edin. 
Dr Richardson, in a recent and elaborate work on the blood, an 
extension of a Prize Essay on the cause of the coagulation of this 
fluid, has endeavoured to prove that this phenomenon is of a chemi- 
cal kind, depending on the escape of the volatile alkali. 
The author of the paper of the above title describes three sets of 
experiments which he has instituted for the purpose of testing Dr 
Richardson’s hypothesis. In all his trials on blood, he has used 
that of the common fowl, its properties being best adapted to the 
objects in view. The results obtained were briefly the following : — 
1. Ammonia added to the blood in small quantities did not pre- 
vent its coagulation; in larger quantities it retarded coagulation, 
and rendered the blood viscid. 
2. On exposing mixtures of blood and ammonia, and of water and 
ammonia, to the open air, the loss of weight sustained in two or three 
minutes — the time required for the coagulation of the blood — was 
hardily appreciable, using a very delicate balance. 
3. The moist fibrin of the blood subjected to the action of am- 
monia was found to be rendered transparent and viscid ; but to be 
very slightly soluble. 
These results, and others, such as the coagulation of the blood in 
close vessels, and the volatile alkali not- having hitherto been de- 
tected in healthy blood, have led the author to the conclusion that 
the phenomenon under consideration still remains an unsolved pro- 
blem ; and that on the ground of mere probabilities it is not easy to 
say which of the two chief hypotheses advanced concerning it — the 
chemical and the vital — is deserving of preference. 
3. On the Recent Vindication of the Priority of Cavendish as 
the Discoverer of the Composition of Water. By Professor 
George Wilson. 
The object of this communication was to direct attention to the 
recent recovery of two documents establishing the priority of Caven- 
dish as the discoverer of the composition of water. Their importance 
vol. iv. 2 d 
