432 APPENDIX. 
water 95 parts). Into an adult cat 300 to 400 cubic centimeters of 
the five per cent. formalin should be injected. 
The cat may now be preserved in a one per cent. solution of 
formalin. Before immersing it in the formalin it is well to remove 
the hair in some way, otherwise this will hold much water and be 
very inconvenient in dissection. The neatest method is to cut off 
the hair with scissors; this takes some time, however. If the skin- 
muscles (p. 93) are not to be dissected, the skin may be removed. 
It is well in-this case to leave the skin on the sides of the head and 
on the feet. 
It is not necessary to open the abdominal cavity, after injecting 
with the five per cent. formalin. If there is at any time reason to 
suspect that the viscera are not keeping well, the abdominal and 
thoracic cavities should be filled with five per cent. formalin by 
making a small hole through the body wall into the cavity, introduc- 
ing a canula, and injecting till the cavity is full. 
The specimen should be kept in a jar or other vessel and should 
be completely immersed beneath the one per cent. formalin. Any 
parts projecting above the fluid may be attacked by mould. If a 
part is found to be moulded, it should be submerged, when the 
mould will be killed. The mould injures the specimen if allowed 
to grow for a long time, but if discovered soon, no very serious harm 
results. 
During dissection, exposed parts of the body should be kept 
from drying by covering with a damp cloth. Specimens preserved 
in formalin dry out much less quickly than those preserved in 
alcohol. 
2. For some purposes it is much more convenient to preserve 
the material without immersing it in a vessel of formalin. Specimens 
injected with five per cent. formalin, as above directed, would usually 
keep perfectly without further treatment, but for two difficulties: 
(1) the specimen may dry; (2) it may be attacked by mould. 
The drying may be prevented as follows: Use for injecting a 
mixture of the five per cent. formalin with one-sixth its volume of 
glycerine. This will dry only very slowly, and if pains are taken to 
keep exposed parts covered with cloths dampened with the mixture 
of formalin and glycerine, there will be no trouble from this source. 
The skin should not be removed from such specimens except as 
necessary in the course of dissection. The hair will give little 
trouble, because dry. 
The specimens should be kept in a tight box, that the fluid may 
not evaporate rapidly from the cioths used for wrapping, 
The attacks of the mould present a difficulty not so easily over- 
come, As long as the specimens are in daily use for dissection, and 
exposed parts kept covered with cloths saturated with the glycerine 
and formalin mixture, little or no trouble is to be anticipated. But 
if the specimens are left untouched for some days, and particularly if 
exposed surfaces are not kept covered in the manner above recom- 
