In those cases where the stomach is found perforated, its bulk is very small; the holes commonly occur in the large and small extremities; their form is circular, and their edges thin, and as if dissolved. The urinary bladder contains no urine, although the patient have not discharged any.
The appearances upon dissection of those who die of the _secondary_ effects are entirely different from those above described. It would be difficult to find an example of greater emaciation, more advanced consumption, or more disgusting form. Nothing is equal to the degree of withering, and decrepitude of the whole organs; their colour is faded; the internal cavities do not contain the usual serum; the cellular and muscular systems are almost annihilated; the bones become dry, as in persons of advanced age, and break with extraordinary facility; but these changes are general and secondary, and depend upon local organic derangement of the alimentary tube. The stomach and whole intestinal canal are contracted to an extremely small size; the intestines are not larger than the little finger, sometimes not exceeding a thick writing quill; their coats are very thick, their cavity almost obliterated, and containing only a little mucosity. The stomach, which often resembles a portion of a small intestine, appears sound externally, and only presents some adhesions to the neighbouring viscera; internally, the most remarkable change is the contraction of the pylorus, the passage through which will scarcely admit a probe; and the membranes of the stomach itself are so thickened and compacted around it, that they have lost all their natural suppleness. On the internal surface, there are irregular spots, or rather smooth and red places, which seem to be covered with a regenerated mucous membrane, less villous than that which had been destroyed by the action of the acid; these cicatrices are particularly large and numerous in the great end of the stomach, and around the circumference of the pylorus.
_Chemical processes by which the presence of Nitric Acid may be discovered._
If the acid be in any quantity, and without mixture, there cannot exist any difficulty in demonstrating its presence. If added to copper filings, there will be a copious disengagement of orange-coloured fumes, and a nitrate of copper of a blue colour will remain, as the product. If it be saturated with potass, we shall at once obtain by due evaporation the well known substance, nitre; this salt will announce its nature by deflagrating with charcoal or sulphur. This latter test is the one we must employ for the detection of nitric acid, when mixed with vinegar, and other liquids. Where the acid has combined with the animal matters with which it may have come into contact, they must be boiled for an hour in a solution of pure potass, when the solution will assume a reddish appearance; this must be filtered, and evaporated in a capsule of porcelain, when the mass so obtained will leave a residuum of nitrate of potass.