ON INJECTING. 271 
during admixture. ‘Test the mixture with blue litmus paper, and 
if not of a very decidedly acid reaction, a few drops more acid 
must be added to the remainder of the glycerine, and mixed as 
before. Lastly, mix the alcohol and water very gradually, shaking 
the bottle thoroughly after each successive portion till the whole is 
mixed. This fluid, like the Prussian Blue, may be kept ready 
prepared, and injections made very rapidly with it.” This is, with- 
out doubt, one of the best fluid injections ever devised. It is 
particularly useful for injecting such lower forms of animal life as 
insects, shell-fish, snails, and small fishes. 
Acetic Acid is to be preferred to Hydrochloric for the purpose 
of acidifying the solution. The object in adding acid to carmine 
injections is to precipitate the carmine, and so prevent it from 
- transuding through the walls of the vessels into which it is thrown. 
DR. CARTER’S CARMINE. 
Carmine : fe OOMatains: 
Liq. Ammonia (B. PD. ws ee LOO MAINS, 
GlacialAcetic*Acidi*!.2! 73.0 "22" 86 minis; 
Gelatine (Gel. 1 part, water 6 ae 2 02. 
Wateruin.: Hi, +. 4 02, 
The Carmine is to be dissolved | in the ammonia and added to 
the water. This solution is added to one half of the gelatine, and 
to the remaining half of gelatine is added the acetic acid. ‘The 
acidified gelatine solution is next mixed drop by drop with the 
portion containing the carmine, and the whole is filtered through 
fine flannel before use. To be successful in making this mass, it 
is necessary to use glacial acetic acid, and the strong liquor 
ammonia of the British Pharmacopceia. 
A good supply of each of these injections should be kept ready 
for immediate use. It is convenient to keep the masses in vessels 
made either of block tin or copper, in order that they may be 
readily heated. They may, however, be kept in earthenware jars 
and melted by placing the jars in boiling water. The fluid injec- 
tions should be kept in stoppered bottles, and the mouth should be 
sufficiently large to admit the nozzle of the syringe. The different 
injections should be filtered occasionally to remove any particles of 
matter which may get into them, and they should be distinctly 
labelled ; this precaution will effect a saving in time and prevent 
mistakes, ; 
THE SYRINGE. 
In selecting a syringe, the following points should be attended to. 
(1) The syringe, which should be of at least one ounce capacity, 
should be furnished with two rings at its upper end, one on each 
side, for the fingers to pass through ; (2) It should also be furnished 
with three pipes or canule of about ;; in, 54 in, and A; in 
32 
