The advance had still to be made from pathology to treatment. Here, so far as England is concerned, honour is again due to Sir Victor Horsley. On 8th February 1890, he published the suggestion that thyroid-tissue, from an animal just killed, should be transplanted beneath the skin of a myxoedematous patient:-- "The justification of this procedure rested on the remarkable experiments of Schiff and von Eisselsberg. I only became aware in April 1890, that this proposal had been in fact forestalled in 1889 by Dr. Bircher, in Aarau. (The date of Dr. Bircher's operation was 16th January 1889.) Kocher had tried to do the same thing in 1883, but the graft was soon absorbed; but early in 1889 he tried it again, in five cases, and one greatly improved." The importance of this treatment, by transplantation of living thyroid-tissue, must be judged by the fact that in 1888 no practical use had yet been made of the scientific work that had been done. The Clinical Society's Report, published that year, gives but half a page to treatment, of the old-fashioned sort; and not a word of hope. Then, at last, in 1891, came Dr. George Murray's paper in the _British Medical Journal_, "Note on the Treatment of Myxoedema by Hypodermic Injections of an Extract of the Thyroid Gland of a Sheep." Later, hypodermic injections of thyroid-extract gave way to sandwiches, made with thyroid gland (Dr. Hector Mackenzie, and Dr. Fox of Plymouth), and these in their turn were eclipsed by tabloids. It is a strange sequence, from 1873 onward: clinical observation, _post-mortem_ work, calamities of surgery, experimental physiology, transplantation, hypodermic injections, sandwiches, and tabloids. And far more has been achieved than the cure of myxoedema. Even if the discovery stopped here, it would still be a miracle that little bottles of tabloids should bring men and women back from myxoedema to what they were before they became thick-witted, slow, changed almost past recognition, drifting toward idiocy. But it does not stop here. The same treatment has given good results in countless cases of sporadic cretinism, restoring growth of body and of mind to children that were hopelessly imbecile. It is of great value also for certain diseases of the skin. Moreover, physiology has gained knowledge of the purpose of the thyroid gland, and a clearer insight into the facts relating to internal secretion. XIII THE ACTION OF DRUGS