FORMALIN FOR THE PRESERVATION OF BRAINS. 



(Preliminary Note.) 



By Pierre A. Fish, D. Sc. 



Instructor in Neurology, Etc., Cornell University, Ithaca^ N. V. 



In October 1893 I published* a method for preserving the 

 brain, which had for its objects a minimum of distortion, rapid- 

 ity of action and economy. It was known as the Zinc-Glycer- 

 ine method. The zinc chloride was added in order to effect a 

 differentiation between the alba and cinerea, and the glycerine 

 to increase the specific gravity of the fluid so that the brain 

 might be supported. 



Experiments with formalin (40 per cent, formic aldehyde) 

 show that practically as good results may be obtained at less 

 cost when the following mixture is employed : 



Water, . . . 2000 cc. 



Formalin, 40 per cent., 50 cc. 



Sodium chloride, . 100 grams. 

 Zinc chloride, . 15 grams. 



The specific gravity should be about 1.05. In practice the 

 brain is left in this mixture for a week or ten days (a longer stay 

 is not detrimental) and when practicable the cavities and blood 

 vessels are injected with the same mixture in order to insure a 

 more uniform hardening. The specimen may then be trans- 

 ferred to I percent, formalin (water, 2000 cc, formalin, 50 cc.) 

 and may remain in this solution indefinitely, if the jar be kept 

 tightly covered ; or if it is to become a museum specimen it 



