Water..................................................... 3 ounces.

II.

Ammonia bromide..........................................240 grains.
Gelatine..................................................24 grains
Water..................................................... 3 ounces.
Hydrochloric acid enough to slightly acidify the solution.

III.
Gelatine................................................. 20 grains.
Water.................................................... 1/2 ounce.
IV.

Hard gelatine (say Nelson's X opaque,
or Mr. A. L. Henderson's)................................240 grains.
Soft gelatine (Nelson's No.1)........................... 240 grains.
Water.....................................................24 ounces.

Nos. II., III., and IV. are allowed to stand until the gelatine is
softened. No. I is then warmed in a hock bottle until the gelatine is
just melted, when No. II. is poured into it, a little at a time, with
vigorous shaking, until the whole is emulsified. It is then transferred
to an ordinary jelly can, which is placed in a saucepan half full of
water over a ring Bunsen burner in the dark room, and boiled for half an
hour. It is then allowed to cool to about 100 deg. Fahr., when No. III. is
added. The whole is then allowed to get quite cool, when it is poured,
with stirring, into about one pint of methylated spirit. If it be wished
the precipitate may now be filtered out and washed at once like an
ordinary filtrate, but I prefer to allow it to settle, which it will do