British Association. elt 
diarrhea or diuresis, nor anaphrodisiasis, and its special properties are 
exerted sooner and with less inconvenience. 
** On the Physiological Properties of the Nitrate of Amyle.” By Dr 
B. W. Ricuarpson.—The nitrate when inhaled produces an immediate 
effect on the heart, increasing the action of the organ more powerfully 
than any other known agent. As the action of the heart rises, the sur- 
face of the skin becomes red, and the face assumes a light crimson colour. 
Carried to an extensive degree, the nitrate excites the breathing, and 
produces a breathlessness like that caused by sharp running or rowing. 
On animals, when the agent is given in large doses, it produces death. 
The most remarkable effect produced by the nitrate was, that in the 
lower animals and frogs it led to suspended animation, which could be 
maintained for so long a time as nine days with perfect after-recovery. 
“On the Blood in Relation to the Question, Is Ammonia one of its 
Normal Constituents?” By Dr Davy.—The conclusions he arrived at 
are the following :—1l. That they are confirmatory of the inference that 
the coagulation of the blood is not owing to the escape of ammonia. 2. 
That they are favourable to the conclusion that the blood generally con- 
tains a small proportion of ammonia. 3. That the ammonia which is 
found in the air, respired in respiration and in insensible cutaneous per- 
Spiration, is derived from the blood, and is yielded in union with carbonic 
acid. 4. That the proportion of the volatile alkali is greater in venous 
than in arterial blood. 5. That in the blood of the Batrachians, and of 
other animals in which the aeration of this fluid is less perfect than in 
birds and mammalia of higher temperature, the quantity of the alkali is 
proportionally greater. 
‘*On the Reason why the Stomach is not Digested by its own Secre- 
tion during Life.” By Dr Pavy.—How is it that the stomach, composed 
as it is of digestible materials, escapes being digested itself, whilst diges- 
tion is being carried on in its interior? The question here raised must 
be admitted to be one of the utmost interest and importance to us all, 
because it touches upon the means by which we escape after every meal 
we consume from the occurrence of an event which would inevitably 
prove fatal to life. Hunter noticed that the stomach was susceptible of 
being attacked by the digestive liquid after death, and accounted for its 
power of resisting destruction during life by reference to the ‘‘ living 
principle.” This statement, however, fails to stand the test of actual 
experiment. The “ living principle’? must be discarded, as insufficient 
to account for the state of security under which the living stomach exists. 
To replace the refuted influence of the “living principle,” it has been 
suggested that-it is the epithelial lining which gives to the stomach the 
immunity from destruction it enjoys during life. This view, however, 
like Hunter’s ‘‘living principle,” fails to stand when submitted to the 
test of experiment; for [have found that a considerable-sized patch of 
mucous membrane may be removed, and food will afterwards be digested 
without the slightest sign of attack being made upon the deeper coats of 
the organ. The problem, therefore, as to why the stomach is not suscep- 
tible of attack during life, as it is after death, still remains open for solu- 
tion; and the view that I have to offer refers the immunity observed to 
the circulation within the walls of the organ of an alkaline current of 
blood. It will not be disputed that the presence of acidity is one of the 
necessary circumstances for the accomplishment of gastric digestion. 
Now, alkalinity is a constant character of the blood, and as, during life, 
the walls of the stomach are everywhere permeated by a current of this 
alkaline blood, we have here an opposing influence, the effect of which 
