7 
and the troth dissipated. The density was then taken a 
second time, and the loss calculated. 
Operating in this way on a specimen of diabetic urine 
sp. gr. 1038*60, the following results were obtained: — 
Sugar, per 100 parts, by the volumetrical method, 7’69. 
Density before fermentation at 60° or D = 1038*60. 
Density after fermentation at 60° or D' = 1005*92. 
Density lost, or D — D' = 32*68. 
The relation, therefore, between the density lost and the 
percentage of sugar, in this instance, was as 32*68 to 7*69, or 
as 1 to 0*235. By numerous trials with diabetic urines, of 
different strength, it was found that the most correct pro- 
portion was as 1 to 0*230. The corresponding formula, 
therefore, was : — 
Sugar, per 100 parts, or S = (D — D r ) X 0*23. 
The accuracy of this method was further tested by operating 
on diabetic urine diluted with known volumes of water or 
non-saccharine urine, and on solutions of loaf sugar in water 
and in healthy urine. 
This method of estimating sugar is especially applicable 
to medical practice, and the following simple and most con- 
venient rule expresses the result of the analysis: — 
Each degree of ‘ density lost ’ indicates one grain of 
sugar per fluid ounce of urine. 
PHYSICAL AND MATHEMATICAL SECTION. 
October 1 1th, 1 860. 
Some conversation took place respecting recent storms, 
and the bearing of the new weather tables, given in the 
Times , on their theory, as Mr. Baxendell remarked that 
