72 THE MICROSCOPE. May 



July 1 it was found well hardened, in clear fluid with but 

 slight indications of shrinkage. 



A camel's tongue, larynxes of spider monkey, camel 

 and kangaroo were cleaned, washed and preserved in from 

 two to four per cent during February and March ; they 

 are at present fine preparations. 



Exper'nneiit 7. Several trial were made to harden and 

 preserve brains, with difl'erent per cents of formalin, with 

 alcohol and formalin, and with formalin and bichromate. 



I will speak particularly of a few : 



1. A brain of a spider monkey removed twenty-four 

 after death was placed in four per cent formalin. In a 

 very few days it was firm, remained white and did not 

 noticeably shrink. July 1, it was all that could be de- 

 sired in a museum specimen. 



2. The brain of a kangaroo was hardened in forty or 

 fifty per cent alcohol and two per cent formalin, equal 



'parts; the results were no better; the specimen was as 

 good and prepared in less time than by alcohol alone ; 

 and of course much more cheaply prepared. 



3. Brains of dogs and cats were prepared for anatomical 

 purposes by adding to the usual bichromate solutions one 

 or two per cent formalin.' A smaller quantity of fluid was 

 necessary, not so many changes and a great gain in time; 

 the material was excellent, not brittle and with fine con- 

 trasts. 



Before stating my general conclusions as regards this 

 agent in preserving museum and anatomical preparations, 

 I would like to add a note as to its usefulness in another 

 direction, viz., in preserving animals for dissection. If 

 the subject is a small dog, its blood vessels are washed 

 out with salt solution and 250 cc. more or less of five per 

 cent formalin injected. Thus prepared and kept in a 

 cool place, when not under examination, it may be used 

 by the dissector day after day and for several weeks with- 

 out unpleasantness. The brains of animals thus treated 



