Page:Proceedings of the Royal Society of London Vol 2.djvu/87

Rh the uterus, at the same time that the eggs are forming within the uterus. When the animal is about to produce a capsule, it fixes itself by the tail, and in the course of ten minutes is seen to become much distended in the region of the uterus, but contracted both above and below that part. The swelling at first has the ordinary dark colour of the animal, but in a few minutes a film is seen to separate, and become of a milky white colour, from the contents of the uterus, which are forcibly emitted into it. The animal itself, being thereby diminished, next loosens itself from the enveloping membrane by forcible elongation of the fore part of the body, and then withdraws its head backwards, as from a collar, leaving two openings in the capsule, which, after contraction, remain visible as dark specks, one at each end. These are the points at which the young ultimately make their escape, being apparently aided by the comparative weakness of these parts of the membrane. At the time that they are hatched the young are nearly colourless, and they continue so for several months with very little enlargement. While young they have the property of swimming at the surface of the water with their bellies uppermost, as has been noticed by Muller in the Hirudo hippoglossi, and as the author has also noticed in two other species of Hirudo.

The author ascribes our having derived but little advantage hitherto from the employment of galvanism in the cure of disease, to want of discrimination with regard to the functions of the nervous system, which he considers as twofold, one properly nervous, the other purely sensorial.

Galvanism, he says, never did perform any of the functions of the sensorial system; it cannot restore hearing to the deaf, or sight to the blind; and yet these are the cases that have been blindly selected for its employment. On the muscles it acts purely as a stimulus, and is not to be expected to do more than other stimuli. But since it appears to have peculiar power over the nervous system, he was led to inquire what diseases depend on a failure of nervous influence; and from having observed the difficulty of breathing brought on by dividing the eighth pair of nerves, and the relief afforded in that case by sending a stream of galvanism through the lungs, he was induced to try the effects of galvanism in habitual asthma, or asthmatic dyspnœa, which he conceived to depend on some obstruction of nervous energy.

In such instances as have come under his own observation, the employment of galvanism has been almost uniformly attended with relief to the symptoms, and in many instances has proved a perfect cure. When it is applied as strong as the patient can well bear without complaint, the relief is often perceived in five minutes, and