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On Acrid Poisons. By G. L. Roupell, M.l). 
A further Report on the subject of Poisons was submitted by 
Dr. Roupell to the Meeting. The object of the author was to 
advance a step in showing the mode of operation of poisonous 
substances. The labours of Dr. Hodgkin and Dr. Roupell had 
hitherto been confined to the description and illustration of ap¬ 
pearances resulting from the direct application of poisons to the 
mucous membranes. Dr. Roupell next proceeded to ascertain 
the effect which poisons produce when introduced into the cir¬ 
culation, and he concluded his paper with some conjectures 
suggested by the facts presented to him as to the probable origin 
of certain forms of disease. 
The mode adopted in the experiments about to be detailed 
was to inject various agents into the veins; some actively and 
intrinsically poisonous ; others poisonous only by their chemi¬ 
cal relation to the circulating fluids. The substances employed 
were arsenic, corrosive sublimate, tartarized antimony, muriate 
of iron, acetate of lead, and kreosote. 
Two results were common to the employment of all. First, a 
fatal termination from the administration of large doses of each; 
and secondly, a complete absence of all symptoms of derange¬ 
ment from the employment of smaller doses even of the most 
virulent. 
The paper was accompanied by several highly finished draw¬ 
ings ; the first of which exhibited the oesophagus, the stomach, 
and part of the duodenum of a dog poisoned by the injection of 
arsenic into the veins. The oesophagus was natural in appear¬ 
ance. The stomach exhibited the hour-glass contraction and con¬ 
tained about an ounce of toughish mucus. The tips of some of 
the rugae were reddened at the contracted part, but it differed lit¬ 
tle from health at either extremity. The mucous membrane of 
the small intestines was acutely inflamed, presenting narrow 
bands about two lines in breadth of a bright red colour extend¬ 
ing transversely across the intestine, alternating with equal 
spaces of apparently sound membrane. This striped appearance 
was chiefly at the upper portion of the small intestines, the in¬ 
flammation becoming more diffused in extent and diminishing 
in degree as it was traced downwards, anti finally terminated at 
the extremity of this portion of the intestinal canal. The details 
of this experiment were as follow. An ounce of a saturated 
