The goats must not come from a high altitude, or their glands will not contain a right amount of iodine. This is curiously important. Dr. Brinkley cannot use goats from Colorado for that reason. If the doctor's reception in England is cordial he will probably make his visit there an annual summer affair of three months' duration for some years to come, which would give him an opportunity of keeping in continued touch with his English and European patients. The English are a practical people, and less sensitive than we to, or more careless of, ridicule, and they are likely to grasp the importance of Dr. Brinkley's work on the instant of his arrival, compelling a long visit. CHAPTER VII PROFESSOR STEINACH AND THE RAT Writing with vivacity and humor, Mr. Clarence Day, Jr., speculates with so much whimsicality upon the possible effects of surgical rejuvenation of men that one might overlook the keenness of his observation in a hurried perusal of his article. For the sake of preserving it for more leisurely study, and because the points raised are really worthy of attention, the article is reproduced here in full, with acknowledgments to +The Literary Review+, in which it first appeared, of date November 20, 1920. Says Mr. Day: Biologists really seem to be discovering ways of making men young again. So far, it is like making men drunk; the state that is produced does not last. But it looks as though they might succeed in adding a chapter to life. I wish it could be added to the other end: to youth instead of to the last flickers. But if we can renew and re-live middle-age, that will be better still. A man named Steinach, in Vienna, has been experimenting for ten years with rats. Full accounts of his work were published last summer in the great biological journal founded by Roux, and these were summarized and discussed by the London +Athenaeum+, which is now the most interesting of all English weeklies. It is from the +Athenaeum's+ account that I am taking these facts. Steinach has been studying the interstitial cells that fill in the spaces between the tubules of the testes, in males, and between the follicles of the ovaries in females. His reason for choosing these cells for his experiments is that they are a well-spring of life. Furthermore, since all our vital functions are interrelated, to make these cells active gives the whole organism new life and strength. This is not the only way of stimulating the organism, but it seems the most powerful.