“Some effects on rabbits of intravenous injections of nicotin,” with demonstrations

A solution of 1 in 200 of the chemically pure nicotin furnished by Merck was used. Of this solution, ⅓ of a c.c., equal to 1 ½ mg. of nicotin, was injected daily into the ear-vein of the rabbits. About ten seconds after such an injection the animal is seized with a typical convulsion lasting from three to five minutes, after which it is apparently entirely well until the next injection, when the same thing recurs. This may be repeated with great regularity and without any exception every day and no tolerance to the poison seems to develop. In two animals it was attempted gradually to increase the daily dose to ⅓ c.c. This, however, proved too dangerous and was abandoned. All animals thereafter received the same daily dose of ½ c.c., which was never increased or diminished. A number of animals died before they had received a sufficiently large number of injections to cause any definite lesion. Death ensued in some instances from some cause not at all referable to the nicotin poisoning, but in others from numerous small infarctions in the lungs, possibly caused by the intravenous injections. Cerebral hemorrhages, which are found so often in rabbits treated with adrenalin injections, were never found in these animals.

In animals which outlived a certain number of injections, various distinct and characteristic lesions were found. It seems, however, that not all animals are equally susceptible. What has been observed in the numerous experiments with adrenalin seems to be true also for nicotin. Now and then, how frequently the authors were not able to say, rabbits are found that will respond to the daily nicotin injection with the typical convulsion, but after months of this treatment fail to show any of the characteristic lesions about to be described.