656 APPENDIX. 
smaller slips for issue, two or more scarifiers, a curette, 
four to six razors for shaving the animals, a razor strop, 
a pair of large scissors, curved on the flat, for clipping 
the animals, a burette from which glycerin flows while 
the vaccine pulp is being ground, burette holder, a 
Doring vaccine grinder, clinical thermometers, to take 
the temperature of the animals, six to twelve small 
glass dishes with covers, a hard-rubber syringe, of four 
ounce capacity, to make suction, absorbent cotton, glass 
vials and corks, and several pounds of soft glass tubing, 
three-eighths of an inch in calibre, to store virus emul- 
sion. There should also be gowns and caps for the 
attendants. Sodium carbonate, bichloride of mercury, 
bromine (for a deodorizer), alcohol, and glycerin are 
the chemicals needed. 
For issue for public vaccinations there are also needed 
packing-boxes, rubber bands, sheet wadding, needles, 
and wooden toothpicks (for removing the virus from 
the vials and rubbing it on the scarifications). 
Yield. The material allowed from the five children 
should vaccinate at least five calves; it may easily 
vaccinate fifteen calves. Ten grammes of pulp and two 
hundred charged slips would be an average yield from 
a calf, and that, when made up, should suffice to vac- 
cinate at least fifteen hundred persons. Calves vary 
immensely in the yield. Of two calves vaccinated in 
precisely the same way one may furnish material for 
five hundred vaccinations and the other for ten thou- 
sand vaccinations. 
The Durability of Glycerinated Virus in Sealed Tubes. 
As a result of testing from time to time an immense 
number of specimens of vaccine, the conclusion has 
been reached that vaccine properly put up should 
