Page:Popular Science Monthly Volume 59.djvu/291

Rh researches of different men of various nationalities, which finally culminated in a practical result.

It was to an American, a well-known physician in New York, that we owe the first suggestion of the idea. Dr. J. Leonard Corning, in 1885, discovered that frogs, those benefactors to the human race on whom so many of the experiments for the good of man have been tried, could get the characteristic reaction of strychnine from very small solutions of the drug if it were injected into the spinal cord. He then bethought him to try the effect of cocaine; he accordingly experimented on dogs, injecting the anæsthetic between the superior processes of the vertebræ, where the numerous minute vessels would carry it to the cord. After a few minutes the dog lost all sensation in its hind legs; it could be pinched and pricked and touched with an electric bnsh without knowing it, but the same treatment applied to its fore legs brought forth yelps and howls.

As there were no evil effects seen in the various dogs on which Dr. Corning experimented, he tried the effect upon one of his patients who had for some time suffered from spinal weakness; injecting sixty drops of a 3 per cent, solution of cocaine into the tissues about the spine, between the eleventh and twelfth dorsal vertebræ. For the space of half an hour the man had absolutely no sensations of pain in his lower limbs; electricity and pin pricks were alike unnoticed, and Dr. Corning might have amputated a leg had his patient needed to lose one of those members, and at one stroke have taken all the fame of the discovery of a new form of anæsthesia; but in an hour or more the patient arose and walked home, with no unpleasant after-effects, except for a slight headache and dizziness. Dr. Corning reported on the frog, and dog, and man, to his medical colleagues, and threw out a general hint as to the possibility of extending the usefulness of cocaine in operations; but there the matter dropped. His experiments were, however, the germ of a new idea.

Some years later, the German investigator, Quincke, devised a method of puncturing the membrane surrounding the cord, so that he might draw out a few drops of the spinal fluid, to see whether, in such a disease as spinal meningitis, for instance, there were any bacteria present, or whether he could discover any characteristics that would help to diagnose certain obscure cases of disease by observing the pressure of the fluid of the spinal cord.

To penetrate to the very marrow of one's backbone would have seemed, fifteen years ago, to toy with the seat of life. Dr. Corning did not go nearer than the nerve tissues near the cord; but, once Quincke had shown that the needle of a hypodermic syringe could be thrust easily and painlessly and accurately into the space surrounding the spinal cord, and that a few drops of the cerebro-spinal fluid might