200 
agitation, and the following recipe is stated to succeed 
admirably, showing vessels of Tooo of an inch, with a clear 
outline even under a \ objective, without any grain or extra- 
vasation of the colouring matter : — 
Take 180 grains best carmine, ^ fluid oz. ammonia, com. 
strength, SG 0‘92, or 15 degrees ammonia meter, 3 to 4 oz. 
distilled water. Put into a small flask, and allow to digest 
without heat 24 to 36 hours, or until the carmine is dissolved. 
Then take a Winchester quart bottle, and with a diamond 
mark upon it the spot to which 16oz. of water extend. The 
coloured solution must then he filtered into the bottle, and to 
this pure water must he added until the whole is equal to 
16oz. Next dissolve 600 grains in potash alum in about 10 
fluid oz. of water, and add to this under constant boiling a 
solution of carbonate of sodium, until a slight permanent pre- 
cipitate is produced. Filter and add water up to 16 fluid oz. 
Boil, and add this solution while boiling to the cold ammonia- 
cal solution of carmine in the Winchester quart, and shake 
vigorously for a few minutes. A drop now placed upon white 
filtering paper should show no colouring ring; should it do 
so, the whole must be rejected. Supposing the precipitation 
to be complete or very nearly so, shake vigorously for half an 
hour, and allow to stand till quite cold ; the shaking must 
then be renewed and the bottle filled up with cold water. 
After allowing the precipitate to settle for a day, draw off 
the clear supernatant fluid with a syphon. Repeat the wash- 
ing till the clear fluid gives little or no precipitate- with 
chloride of barium. So much water must be left with the 
fluid that at last it must measure 40 fluid oz. For the 
injection fluid take 24oz. of the above coloured fluid and 3oz. 
of good gelatine, allow these to remain together all night, 
then dissolve by the heat of a water bath, after which it 
should be strained through fine muslins. On injecting:, the 
ordinary precautions for a gelatine injection arc alone neces- 
sary. 
