NEW METHOD FOR APPLYING THE RABIES TEST. 
25 
piece of the brain substance of the suspected animal is ground 
in a sterile mortar containing 5 cc. of sterile .6# sodium 
chloride solution, and is filtered through sterilized cotton. The 
resulting filtrate should be of the consistency and color of milk. 
About two minims (four drops) of this suspension are injected, 
by means of a hypodermic syringe having a very fine needle ]/% 
inch long, on to the base of the anterior cerebrum, above the 
dura-mater by way of the optic foramen. Although this fora¬ 
men in rabbits is relatively very large, and there is little risk 
of damaging other structures, if the operation is carefully done, 
the nature of the operation precludes one’s becoming expert in 
passing the needle through the foramen by practice upon live 
rabbits; therefore, it is wiser to gain the necessary experience 
by repeated trials upon dead animals, before attempting the in¬ 
oculation. When full-grown rabbits are used, it will be found 
that the inch-long needle is of about the right length to just 
pass through the foramen and the dura-mater, if pushed in up 
to the nozzle of the syringe. In performing the operation, the 
rabbit is thoroughly anaesthetized and held so it will rest upon 
its chest and abdomen. The head is grasped with the left 
hand and the syringe is held in the right hand. The right 
nictitating membrane is lifted out of the way by means of the 
syringe needle, which is then passed backward and upward 
through the conjunctival sac and orbital tissues until it is made 
to enter the optic foramen. The syringe barrel is now firmly 
held by the thumb, second, third and fourth fingers, with the 
fore-arm at rest upon the table and the piston is pushed up 
with the index finger until it is stopped by the traveling nut 
which had been previously set at a point to allow two or three 
minims of the virus to be expelled. The needle is carefully 
withdrawn and the rabbit is allowed to recover from anaesthesia. 
It is obvious that if too much material be injected, or the 
needle be passed far enough to injure the brain, the rabbit may 
die from brain pressure or from brain injury. Frequently, a 
rabbit will show symptoms of slight brain pressure, but these 
pass off as soon as the pressure is removed by the dispersion of 
