On Glycosuria caused by Excess of Carbon-Dioxide in the Respired Air.

For the purposes of a research upon the effects on the respiratory exchanges and metabolism of varying the percentage of oxygen in the air breathed, a specially constructed apparatus was devised in which animals under experiment (usually cats) could be kept for as long a period as was desired in an atmosphere containing a constant percentage of oxygen, the carbon-dioxide produced by the animal being absorbed almost as rapidly as it was formed by a large quantity of soda-lime placed in the chamber. One of the main objects of the enquiry being that of studying, in addition to the gaseous exchanges, the metabolism of the animal as shown by the urine; it was a routine procedure in all cases to examine the urine for abnormal constituents, and in particular for the products of incomplete oxidation, in those cases in which the percentage of oxygen was made less than that in the atmosphere. Amongst such constituents dextrose was always tested for in the urine, and was invariably found to be absent, even when the animal had been kept in an atmosphere containing 5 to 6 per cent. only of oxygen for a period of several hours, provided that the carbon-dioxide formed during the period had been efficiently removed by the sodalime placed in the respiratory chamber. On one occasion, however, the soda-lime failed for some reason to act sufficiently in absorbing the carbon-dioxide, so that at the end of an experiment of i6 hours duration, the respiratory chamber was found to contain IO03 per cent. of carbon-dioxide and 7-7 per cent.