These experimental facts, together with observations by Dr. Sajous, prove that the atheromatous condition brought about after using certain drugs, such as alcohol and tobacco, can be ascribed to the adrenals. Josué, in 1893,[199] showed that by injecting adrenal extracts (solution 1:1000) into the veins of a rabbit, atheromatous patches of the aorta will appear after five or six weeks. The changes described by Adler and Hensel from the effects of nicotine confirm the probability that tobacco acts on the adrenals first, then, by their medium, on the blood-vessels (see, also, Chapter XLIII). Footnote 199: C. R. Soc. biologie, Nov. 14, 1893. The above observations show that the same is also probable in the case of alcohol, to which we may add a case of Widal and Boivin, who found in a young woman dipsomaniac a hyperplasia of the adrenals and atheroma of the aorta; and to complete the value of these observations we subjoin those of a series of cases of atheroma by Joshua, in three of which a hyperplastic condition of the adrenals was found. It follows logically from the foregoing effects of alcohol and tobacco, that we must avoid large quantities of these substances if we desire to keep in a normal condition the heart and blood-vessels, upon the perfect state of which depends, in a great degree, our chances of a long life and extended youthfulness. We will deal further with the latter points in the following chapter. ------------------------------------------------------------------------ CHAPTER XVI. HYGIENE OF THE ADRENALS AND OF THE CIRCULATORY SYSTEM—A FEW REMARKS ON THE CAUSE, PREVENTION, AND TREATMENT OF ARTERIOSCLEROSIS. IN order to obtain the best hygienic condition of the circulatory system, it is indispensable to avoid all that are harmful to the adrenals. There can no longer be any doubt that these glands exercise a controlling influence on the heart and the whole circulatory system. They are in intimate relation with the principal nerves that regulate the heart: the sympathetic and the vagus. Thus, for instance, emotions that act on these nerves excite through them a hypersecretion of the adrenals and a contraction of the small blood-vessels, with a rise in the blood-pressure. By the hyperactivity of these glands their secretion, in larger quantity than usual, is thrown out into the system, producing toxic effects which result in an atheromatous condition of the arteries. According to our present knowledge, we imagine this atheromatosis to be due to the toxic effect of the adrenals quite independently of the increase in the blood-pressure, for it has been distinctly shown that even substances which diminish blood-pressure, such as amyl nitrite, for example, are also capable of producing atheroma. The toxic effects of adrenalin are proved by the experiments of Amberg[200] in the laboratories of the Johns Hopkins University. Footnote 200: