actly at 7 a.m., and add it to what has previously been
passed.

_Qualitative Sugar Tests._

(1) Fehling's Test:--Boil about 4 c.c. of Fehling's[1] solution in a
test tube, and add to the hot Fehling's an equal amount of urine, a
few drops at a time, boiling after each addition.

A yellow or red precipitate indicates sugar.

For practical purposes in the following of a diabetic's daily urine,
this is a valuable test, and the one which we always use.

(2) Benedict's Test:--To 5 c.c. of Benedict's[2] reagent add 8 drops
of the urine to be examined. The fluid is boiled from 1 to 2 minutes
and then allowed to cool of itself. If dextrose is present there
results a red, yellow, or green precipitate, depending upon the
amount of sugar present. If no sugar is present the solution may
remain perfectly clear or be slightly turbid, due to precipitated
urates.

This is a more delicate test than Fehling's.

[1] Fehling's solution is prepared as follows:

(a) Copper sulphate solution: 84.65 gm. of copper sulphate
dissolved in water and made up to 500 c.c.

(b) Alkaline tartrate solution: 125 gm. of potassium hydroxide
and 178 gm. of Rochelle salt dissolved in water and made up to
500 c.c.

These solutions are kept in separate bottles and mixed in equal
volumes when ready for use.

[2] Benedict's solution has the following composition:

Copper sulphate, 17.8 gm.
Sodium citrate, 178.0 gm.
Sodium carbonate (anhydrous), 100 gm.
Distilled water to 1000 c.c.

_Quantitative Sugar Tests._

(1) The Fermentation Test:--The fermentation test is the simplest
quantitative test for sugar, and is quite accurate enough for clinical
work. It is performed as follows: The specific gravity of the 24 deg.
urine is taken, and 100 c.c. of it put into a flask, and a quarter of
a yeast cake crumbled up and added to it. The flask is then put in a
warm place (at about body temperature) and allowed to remain over
night. The next morning a sample of the fermented urine is tested for
sugar. If no sugar is present the urine is made up to 100 c.c. (to
allow for the water that has evaporated) and the specific gravity
taken again. The number of points loss in specific gravity is
multiplied by .23, and this gives the percentage of sugar in the
urine.

(2) Benedict's Test:--The best quantitative test for dextrose
(excepting polariscopic examination, which is too complicated