These special meat matters are found concentrated in the gravy. Meat gravy, in fact, beside a feeble proportion of albuminoid matters, or solubly derived quantities, polypeptides, etc., in notable proportion of liberated acids, contains a certain quantity of matters, qualified by the generic name of extractives; a notable quantity of these extractive matters being creatine and creatinine, as well as substances of which the fundamental nucleus is the puric grouping. These purins, by the name which E. Fischer attributes to them, derive from a special grouping which it would be supposed exists in a hypothetic body, but which is not known in a state of liberty, purin. This first term gives rise to a series of bodies in lateral groups, of which the most interesting are caffeine and theobromine. Amongst these substances the one which has the maximum of oxidation is no other than uric acid. Caffeine and theobromine enjoy nervine properties and energetic vascular actions. These properties minutely studied are utilised every day for therapeutic purposes. It is probable that the other bodies of the series which are met with in the extract of meat enjoy analogous physiological properties. These substances are ingested without discernment, often in great excess, and daily, by people who consume meat. Amongst these latter, many would not dare to drug themselves with a centigramme of pharmaceutic caffeine, whereas they absorb each day gr. 5 and more, of its homologous constituents. Therefore, in the same way as chocolate, tea and coffee, meat has a stimulating effect on the system. He who is accidentally deprived of it finds that he experiences a passing depression. This obviously proves that by the exaggerated use of meat, one drugs and doctors oneself without discernment. However this may be, the judicious part played by meat must apparently be reduced to that of a condiment food destined to produce in a measure the whipping-up which is useful, and sometimes indispensable to the system. We cannot here discuss the expediency of action and the harmlessness of the dose of substances reputed stimulating. But one can ask oneself whether, to attain this object of stimulation, carnivorous feeding is indispensable, and if vegetarianism could not supply the need.