10

       5. The freezing-point of the urine.—So far as our observations go on the
freezing-point of the urine of the Bengali—and we have made some hundreds
besides those recorded on Table I—they would appear to show that the
depression of the freezing-point varies directly with the specific gravity in normal
urine and nothing of much importance can he learned by its determination that
is not equally well shown by taking the specific gravity accurately. This
subject.has already been dealt with in another paper.⁽¹⁾

       As would be expected from the lower specific gravity and lower total
quantity of solids, the urine of the Bengali causes less depression of the freezing-
point than is the case in Europeans.

       The average freezing-point of the urine for students is—1.52° C; for
durwans and bearers—1.35° C, and for domes and mehtars—1.01° C; on the
whole series the average obtained was—1.24° C.

       The variations met with are very great—ranging between—0.68º C and .
—2.45° C. In Europeans the freezing-point is usually—2° C to-2.6° C.

       With regard to the question of the value of the determination of the
freezing-point as a means of measuring the work done by the kidney we cannot
agree with the view that the quantity of urine passed multiplied by the difference
in the freezing-points of the urine and blood—the formula Q (Δ—D)—is any
index of the work of the kidney in excretion.

       We have many observations in which the freezing-point of the urine was
actually less depressed than that of the blood, which would mean that the work
of the kidney was a negative quantity; and yet a large quantity of dilute urine
containing quantitatively the normal amount of solids was being voided. For
further information on this point we would refer to Hill and Moore's work on
the subject.⁽²⁾

       6. The Chlorides.—An examination of the quantity of chlorides was made
in every instance, as it was expected the percentage and total quantity present
would be high on account of the largely vegetable character of the diet. In
Europeans the average quantity excreted per day is about 15 grammes, varying
directly with the amount ingested with the food.

       The variations in the amount excreted met with in Bengalis will be seen
from Table I to be from 4.35 grammes to a maximum of 19.30 grammes on
the average figures of four or five consecutive daily analyses.

       The average excretion of chlorides over the whole series of analyses is
9.43grammes daily,—a quantity considerably lower than the average for
Europeans.

                        ⁽¹⁾ McCay.—The Lancet, 1st June 1907.

                        ⁽²⁾Hill.—Recent Advances in Physiology and Bio-Chemistry, 1907.