“In many cases of nervous depression we find a feeling of weakness and prostration coming on during digestion, and becoming so very marked about the second hour after a meal has been taken, and at the very time when absorption is going on, that we can hardly do otherwise than ascribe it to actual poisoning by digestive products absorbed into the circulation. From the observation of a number of cases, I came to the conclusion that the languor and faintness of which many patients complained, and which occurred about eleven and four o’clock, was due to actual poisoning by the products of digestion of breakfast and lunch; but at the time when I arrived at this conclusion I had no experimental data to show that the products of digestion were actually poisonous in themselves; and only within the last few months have I seen the conclusions to which I had arrived by clinical observation, confirmed by experiments made in the laboratory. Such experiments have been made by Professor Albertoni, of Genoa, and by Dr. Schmidt-Mühlheim, in Professor Ludwig’s laboratory at Leipsic.” “Professor Albertoni and Dr. Schmidt-Mühlheim independently made the discovery that peptones prevented the coagulation of the blood in dogs, and the latter, under Ludwig’s direction, has also investigated their action upon the circulation. He finds that, when injected into a vein, they greatly depress the circulation, so that the blood-pressure falls very considerably; and when the quantity injected is large, they produce a soporose condition, complete arrest of the secretion by the kidneys,[20] convulsions, and death. From these experiments it is evident that the normal products of digestion are poisons of no inconsiderable power, and that if they reach the general circulation in large quantities they may produce very alarming, if not dangerous symptoms.” [Footnote 20: See “Bright’s Disease.”]