rops of urine
are added. If no change appears, it is boiled again and a few drops
more of urine are added. If a reddish precipitate appears, sugar is
present. The chemical reaction taking place is the reduction of copper
sulphate to cuprous oxide. Sometimes a partial reduction occurs when
urates are in excess, but once having seen the real reduction, a
partial one cannot mislead the examiner.

~Haines's Test.~--Pour 1 teaspoonful of Haines's solution into a test
tube and boil gently over a Bunsen burner; add 6 or 8 drops of urine
and again heat to boiling. A yellow or red precipitate will indicate
the presence of glucose.

QUANTITATIVE TEST FOR SUGAR

~Benedict's Test.~[110]--The simple quantitative test for sugar is the
one devised by Benedict. This is simpler than the polariscopic
examination and better suited for ordinary use.

Place 5 c.c. of Benedict's quantitative solution in a small dish, add
a little less than one-fourth of a teaspoonful of sodium carbonate and
one-eighth of a teaspoonful of talcum and add 10 c.c. of water. Dilute
urine (1 part urine to 9 parts water) except where the qualitative
test showed a low percentage of sugar, that is, when the precipitate
turns green instead of yellow, in which case it will be unnecessary to
dilute the urine. Place dish over burner and bring the contents to a
boil. Pour the urine into a graduated pipette. Now add the urine drop
by drop to the contents in the dish until the blue color entirely
disappears. This test should be done over several times to assure an
accurate calculation. The calculation is made as follows: 5 c.c. of
Benedict's quantitative copper solution are reduced by 0.01 gram of
glucose, consequently the quantity of undiluted urine required to
reduce 5 c.c. Benedict's solution contains 0.01 gram of glucose.

0.01
------ x 100 = per cent. _x_ = c.c. of undiluted urine.
_x_

Example; 1500 c.c. urine in 24 hours. 5 c.c. used to reduce
(decolorized) Benedict's solution.

0.01
------ x 100 = 0.2 per cent.
5

1500 x 0.002 (0.2 per cent.) = 3 grams of sugar in 24 hours.

Example: If the urine had been diluted with 9 parts water, in other
words, 10 times, the calculation would be 5 c.c. diluted urine = 0.5
c.c. actual urine.

0.01
------ x 100 = 2 per cent.
0.5

1500 x 0.02 (2 per cent.) = 30 grams of sugar in 24 hours.

Hill and Eckman perform the Benedict's quantitative test as
follows:[111]

Measure with a