Articles: animals.
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The chemical changes in the blood of dogs treated with various inorganic salts after obstruction of the duodenum are reported. Two dogs treated with sodium chloride survived approximately six times as long as the average untreated animal, one living 22 days, the other 24 days. Ammonium chloride was found to produce an acidosis. ⋯ Sodium bromide appears to have an inhibitory action upon it, but much less than that of sodium chloride. Sodium sulfate, magnesium sulfate, sodium citrate, monosodium phosphate, and disodium phosphate failed to alter the course of the intoxication. Atropine and pilocarpine were without therapeutic value in preventing the changes characteristic of intestinal obstruction.
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Examinations of fresh blood from yellow fever patients by means of the dark-field microscope, made in more than twenty-seven cases, revealed in three cases the presence of Leptospira icteroides. In no instance was a large number of organisms found, a long search being required before one was encountered. The injection of the blood into guinea pigs from two of the three positive cases induced in the animals a fatal infection, while the blood from the third positive case failed to infect the guinea pigs fatally. ⋯ When death occurs these organs seem to have lost most of the leptospira) and positive transfer by means of them is less certain. At the later stage of the disease the blood is often free from the organisms and ceases to be infective. Positive transmission with blood obtained from moribund animals is not impossible, however, even when no leptospira can be detected under the dark-field microscope.
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The results of these experiments are definite. There is, in the first place, a very striking difference with regard to precipitate formation between the acid and alkaline solutions of salvarsan when injected intravenously. Intravenous injections of alkaline solutions of salvarsan produce no precipitate in the blood, while injections of the acid solution nearly always give a precipitate. ⋯ While in a one tenth per cent. solution twenty and thirty milligrams per kilo of body weight of the acid solution may be injected with impunity, even six or seven milligrams per kilo may prove rapidly fatal when injected in a one half per cent. solution. Our own results, however, leave us with two puzzling questions : First, if the acid solution of salvarsan causes such a coarse precipitate in the right ventricle and in the lungs, how does it happen that this precipitate does not bring about the death of the animal? Second, what is the real cause of the remarkable fact that this precipitate does not pass over into the arterial side of the circulation? Does the precipitate undergo a profound chemical or mechanical change while it passes through the lung capillaries? In future investigations we may try to answer these interesting questions. For the present, it is necessary to be content with the establishment of the bare facts as they are presented in the conclusions.