272 THE MICROSCOPICAL NEWS. 
diameter ; and in order that they may be secured firmly in the 
vessels whilst making an injection, they should be provided with a 
pair of arms to pass the ligature round; (3) The piston should fit 
the cylinder so accurately that if the nozzle of the syringe be 
closed with the finger, and the piston be drawn up, it will, on being 
released, instantly return to its former position; (4) The syringe 
should be provided with a stopcock. A syringe of this kind costs 
about 15/-. If the beginner does not desire to go to so much 
expense, a glass syringe costing about 1/- may be used. The 
canule can be made out of glass tubing, by drawing it to a fine 
point in a Bunsen’s flame, and then cutting off the part required. 
ON DESTROYING THE LIFE OF AN ANIMAL INTENDED 
FOR INJECTION. 
The life of an animal intended for injection is destroyed most 
easily and in the best manner by opening it from anus to throat, 
and cutting deeply into the heart across the right auricle. This is, 
of course, done whilst the animal is under the influence of chloro- 
form, or even immediately after it has been suffocated by chloroform. 
To facilitate the bleeding, the animal should be suspended alter- 
nately by the hind and front legs, and as the blood coagulates in 
the wound in the heart, it should be removed. ‘The best way to 
administer the chloroform is to place the animal in a box, drop in 
a piece of cotton wool saturated with chloroform, and close the lid. 
In from five to fifteen minutes the animal will be dead. Half an 
ounce of chloroform is quite sufficient to kill any cat, and the same 
quantity should suffice for a dog a foot high. 
ON INJECTING A WHOLE ANIMAL. 
A young animal is best for this purpose. A rabbit is, perhaps, 
the best subject for a beginner to select. After having killed it, 
immerse the body in hot water for about fifteen minutes ; then take 
it out, pass a ligature round the aorta close to the heart, make a 
longitudinal incision in the aorta, and insert the canula of most 
suitable size. Bind the canula firmly in the artery, and attach the 
stopcock. Oiled worsted is the best substance which can be em- 
ployed for tying the pipes in the vessels ; it should not be drawn 
too tight or it will cut through them, and so permit the pipe to 
come out. A// vessels must be opened longitudinally, zo¢ trans- 
versely, or they would probably contract so much as to exclude the 
possibility of making an injection. 
A good supply of hot carmine mass (Dr. Carter’s Carmine) should 
be ready for use. Fill first the syringe with the injection and then 
the stopcock and canula. Then insert the nozzle of the syringe 
into the stopcock, taking care that in doing this no air is admitted, 
or it will be forced into the vessels, and the passage of the fluid 
impeded. These points having been attended to, the injection should 
