166 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
of 25, 50, or 100 c.c, and carefully weighed to definite amount, corresponding, when 
the flask has been filled by the solvent under experiment, to a definite percentage of 
chloroform. A series of such flasks is prepared, and immediately after each flask is 
filled with the desired solvent and either shaken thoroughly by hand until solution is 
complete, or placed on a rotary shaking machine. After the lapse of several days, 
during which time the flasks are never opened and are kept shaken up, it is noticed 
at what level of concentration the chloroform ceases to be completely dissolved, and 
so the solubility is determined 
The lower strengths of known value short of saturation and also the saturated 
solutions so prepared were kept and used also for the experiments on vapour pressure 
at varying concentration described in the next section of this paper. 
The following results were obtained by the application of this method at room 
temperatures, approximately (13 0 C), for the percentage by weight dissolved : — 
Water, o*8 per cent, dissolved, 0*9 per cent, dissolved, 1 per cent, not dissolved 
completely. Estimated solubility, 0-95 per cent. 
Saline Solution (0-75 per cent, sodium chloride in water), 0*7 per cent, dissolved, 
o - 8 per cent, dissolved, 0-9 per cent, not dissolved. Estimated solubility about 
0-83 per cent. 
Serum, 3 per cent, dissolved, 3-5 per cent, dissolved, 4 per cent, all dissolved 
save a few small globules. 
Haemoglobin Solution or Blood. — Over 6 per cent, by weight is taken up when 
.chloroform is shaken with blood or haemoglobin solution of equal strength to the 
blood, prepared from blood by centrifugalizing several times with saline and 
subsequent laking with distilled water, and no globules of chloroform can be seen on 
careful examination with the microscope. But the solution rapidly changes in colour, 
and a precipitate is thrown out on standing, as above described, which is quite 
insoluble in water or saline, but easily soluble in dilute sodium carbonate solution, 
and then gives the spectrum of alkaline haematin. 
The blood begins to give this precipitate when about 1-5 per cent, of chloroform 
has been added at room temperature, but with a lower concentration, and more rapidly 
when heated to body temperature in the incubator. Two per cent, of chloroform 
gives a precipitate in the cold, and on heating to 40 0 C. a red flocculent precipitate 
leaving a clear colourless fluid above. 
The third method for determining the solubility of chloroform in the fluids 
experimented with consists in shaking up thoroughly for several hours with an excess 
of chloroform, and then pipetting off and determining the amount of chloroform 
in the solution. 
The difficulty here is a rapid and accurate method of determining the amount 
of chloroform contained in a measured volume of the given saturated solution. 
