But, if this condition of the excretions cannot be attained in a given individual in the desired degree, the organism is suffering from an imperfection that occurs in a normal manner (an excretion of sugar) to a certain degree and extent, such as the physiological potentialities of a living organism permit.
In one connection only, in which it afforded me practical assistance for my observations, this question has not yet been fully elucidated. Sex had not been taken into consideration during the examination of the excretion of sugar within normal physiological bounds. Whilst I was looking through the experiments of the specialists whom I have mentioned, it struck me that most of the inquiries respecting the presence of sugar in normal urine had been made in the case of men alone, and that, so far as regarded the presence of sugar, the urine of the human female had been little observed, and never quantitatively and qualitatively compared with that of man. Nicolai Ivanoff, in his dissertation (Dorpat) on the question of glycosuria in the case of pregnant women, lying-in women, and suckling women, arrived at the following final results: "A physiological glycosuria in the case of the pregnant, or of those who are lying in, has, so far as present investigations have gone, never been established, and certainly not to the extent which Blot asserts. Sugar occurs in human urine more frequently than has been hitherto supposed, but absolutely never _in constant and increased quantities in that of pregnant and lying-in women_."
If, however, it has been in many cases asserted that there was an increased quantity of sugar in the urine of pregnant and lying-in women, and that this has been proved, these statements have originated from mistaking for a previously developed sugar one which has during the experiments come into existence from the action of alkalies and acids on an extractive substance which requires further examination.
For the detection of sugar in the urine several methods exist, which are more or less sensitive.
If we mix a few cubic centimetres of urine with an equal quantity of 10 per cent. solution of caustic potash, and warm a portion of this in a test-tube, we observe that the fluid in the event of a sensible quantity of sugar being present, acquires a color varying from dark yellow to yellowish brown. We can most easily assure ourselves of this if we warm only the upper part of the fluid contained in the test-tube, whereupon the upper part of the fluid will appear darker than the rest.