17

15—20; the quantity thus obtained was collected in a weighed
flask.

   In this way we not only got sufficient blood to carry out analyses, but
also obtained the average composition over the number of indivi-
duals whose blood was taken.

   Having weighed the flask and blood, by deducting the weight of the
empty flask, we had the weight of the blood made use of.

   This was examined for total nitrogen by Kjeldahl's method and the
result noted.

(b) In a similar way the blood was "pooled" into a platinum dish—
weighed before and after.

   From this blood water was evaporated off in a water bath and then in
a dessicator. On weighing again we obtained the total solids
remaining, and the water evaporated.

   The solid matter was incinerated in a red hot flame to get rid of all
organic material and, this being completed, the capsule was weighed
again and the inorganic salts present estimated.

   In Table V we present the averages of the results thus arrived at
regarding the blood of the Bengali.

Table V.

(c) Another method of examination made use of on a fairly large scale
was the estimation of the total salt concentration of the serum
(expressed in terms of NaCl) by Wright's hæmolysis method.
This is an exceedingly simple and easily carried out means of ex-
amining the blood. A full description of the method will be found
in Wright's original papers; ⁽¹⁾ its application to the Bengali has
already been worked at. ⁽²⁾

        ⁽¹⁾ The Lancet-2nd April 1904 and 21st October 1905.

        ⁽²⁾ M'Cay—The Lancet, 1st June 1907.

D