On Acrid Poisons. By G. L. ROUPELL, M.D.

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 appearances 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 circulation, 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 chemical 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 derangement from the employment of smaller doses even of the most virulent.

The paper was accompanied by several highly finished drawings; 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 appearance. The stomach exhibited the hour-glass contraction and contained about an ounce of toughish mucus. The tips of some of the rugæ were reddened at the contracted part, but it differed little 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 extending 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 inflammation becoming more diffused in extent and diminishing in degree as it was traced downwards, and 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

solution of arsenic, made by boiling distilled water with an excess of arsenious acid and allowing it to cool, was thrown by means of a small syringe, at two o'clock P. M., into the femoral vein. For 3 minutes there was no obvious effect, but at the end of that time vomiting commenced, and a quantity of half-digested food was thrown off the stomach. The respiration then became hurried and the animal appeared faint. In 10 minutes there was great intestinal movement, the abdomen being frequently and forcibly drawn in. After 25 minutes, vomiting was renewed, paralysis of the hind legs came on, and the animal died in 65 minutes. Examination was made on the next day. The limbs were rigid, the blood was fluid, the lungs were collapsed and had a rosy tint, but were not inflamed. The peritoneum was reddish. The appearances of the stomach and small intestines have been already described. The large intestines contained solid fæcal matter and were quite free from morbid alteration. There was no apparent change in the mucous membrane of the trachæa or bronchi, none in the inner lining of the heart, veins, or arteries, none at least in their larger branches.

The points of interest in this experiment are, first, the absence of inflammation in so many tissues with which the poison must have come into contact; secondly, its action on the mucous membrane alone; thirdly, the predilection shown for the mucous membrane of the small intestines, and in this instance the limitation of its action to that part of the alimentary canal, where it was intense, the membrane being covered with a layer of tough mucus mixed with blood; fourthly, a circumstance frequently observed in cases of poison, the rigidity of the limbs, the blood remaining fluid.

A second drawing exhibited also the stomach and part of the duodenum of a dog poisoned with arsenic thrown into the veins. In this instance the mucous membrane both of the stomach and intestines was intensely red, the redness extending throughout the whole track of the intestinal tube. This experiment was a modification of the last, the difference consisting in the greater strength of the animal and a diminution in the quantity of the poison. An ounce of a saturated solution of arsenious acid was indeed here also employed, but the solution was filtered; a thin floating pellicle of arsenic was removed from its surface. The solution was thrown into the femoral vein at 12 minutes past 1. The animal vomited almost immediately after the operation. 12 minutes solid fæcal matter was passed from the bowels followed by tenesmus; in 35 minutes dysentery was induced, and the animal made attempts at vomiting. These symptoms continued with more or less severity about 3 hours, when death took

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place. Examination was made 22 hours after; the lungs were red throughout and gorged in patches. The stomach externally was very vascular. The whole of the mucous membrane from the cardiac orifice of the stomach to the extremity of the rectum was in the highest possible state of inflammation. The stomach contained about 4 ounces of a frothy mucus mixed with blood, and a small quantity of a similar secretion was found coating the intestines. The inner lining of the urinary organs was redder than natural. The lining membrane of the heart, large arteries and veins was in its healthy condition.

In this case a longer interval between the administration of the poison and death gave time for the establishment of inflammation in more situations, and allowed it to proceed to a greater extent in those parts which were irritated in the preceding experiment.

A third drawing exhibited the large intestine of the same dog, showing the degree of inflammation in that portion of the alimentary canal.

It may here be observed that half an ounce of the saturated solution of arsenious acid produced in several instances no symptom of ailment even when injected into the veins.

Various experiments were made by Dr. Roupell with corrosive sublimate in solution. Half an ounce of the liquor hydrargyri oxymuriatis P. L. which contains a quarter of a grain of corrosive sublimate, injected as before into the veins, gave rise to no apparent inconvenience.

The injection of a whole ounce containing half a grain of sublimate produced marked discomfort to the animal, followed by severe vomiting and dysentery. But although the symptoms of irritation in the abdomen were urgent, and the dejections proved the highly inflammatory state of the bowels, yet death did not ensue from that quantity.

Dr. Roupell's next experiment was made with tartarized antimony, with the vinum antimonii tartarizati of the London Pharmacopoeia. An ounce of this liquid was thrown into the saphana vein of an active terrier dog. The vinum antimonii tartarizati contains two grains of tartarized antimony, and rather more than a drachm of rectified spirit in the ounce. The immediate effect of this injection was to produce intoxication. The animal was able to move about; but his legs failed him, he seemed giddy, and his gait was staggering. No other effect was apparent for half an hour, and as the dog then seemed but little affected, it was left, under the supposition that the spirit had prevented the action of the tartar emetic. But when the animal was visited some hours afterwards it was found dead and stiff.

Judging from the appearance of the place where it had been confined and from the state of the jaws it was evident that vomiting had taken place. Examination was made next day. There was no morbid appearance in the brain; no morbid appearance indeed was detected anywhere except in the stomach, and that afforded a striking contrast to the other parts of the intestinal canal. These were of their natural white colour, while the stomach was of a vivid red, showing a high state of vascularity, great local determination, and intense inflammatory congestion. As the inflamed part presented no distinguishing peculiarity, it was not considered worth while to employ an artist to copy it. The stomach was inflamed throughout, and the in. flammation extended from the cardia to the pylorus, not uniform however in degree, for the redness was greater at the larger end. This effect is so constant when all parts of the stomach have been equally exposed to the action of irritants as to induce the belief that there must be some difference in the vascularity of the two portions. The author had originally supposed that this inequality in the action of irritants was probably owing to the greater rapidity with which all matters passed over this part of the digestive tube, but he was inclined to believe from the diminished redness in this case that some other cause, and that probably a lower degree of vascularity, exists in this situation.

Although it may be presumed that the alcohol contained in the antimonial wine had delayed the effect of the tartarized antimony, yet it does not appear at all to have mitigated it, as it could hardly have been supposed à priori that death would have taken place in a dog from two grains of tartar emetic.

Dr. Roupell states that he made many other experiments which did not furnish results sufficiently precise to merit enumeration, or to which the effect produced could be distinctly referred to one cause. Thus when a solution of metallic salts have been injected into the veins, as the tinctura ferrimuriatis, or the liquor plumbi acetatis, death has been quickly occasioned and the mucous membranes of the abdomen have presented a marked red appearance; but he has been unable to satisfy himself how far such changes were due to the presence of the metallic oxide, or how far they were the simple consequence of the acid. Either of these substances would produce one effect, the immediate coagulation of the blood, or would predispose to that condition. Not indeed that the mere coagulation of the blood in the veins will occasion any alteration whatever in the mucous membranes, none at least has been observed from the injection of the substance which has the greatest power in coagulating albumen, "kreosote," into the saphæna vein. No altera