56 Neurological Technique 



E. Imbedding media. — 



1. Thin celloidin. — 



Celloidin (thoroughly dried), 5 g. 

 Ether-alcohol (D), 100 cc. 



2. Thick celloidin. — 



Celloidin (thoroughly dried), 13 g. 

 Ether-alcohol (D), 100 cc 



F. Clearing fluid. — 



Carbolic acid (melted), or creosote, 50 cc. 

 Oil of thyme or cedar wood, 50 cc. 

 Bergamot oil, 25 cc. 

 Pure creosote will do for clearing, but sections do not cut in it so well, nor 

 does it mix so readily with balsam, which follows in the mounting, as when 

 mixed with the oils. 



PROCEDURE. 



The modifications of the Golgi method are many and varied, 

 and all are more or less inconstant in their results. The two 

 here given are thought to possess the qualities of being more 

 constant in their results, of having a more general application, 

 and of requiring less time in their procedure. 



The first given, " the rapid method," is especially adapted to 

 foetal nervous tissue. When applied to adult nervous tissue, its 

 failures are much more frequent. 



The second modification has been found especially efficient 

 for the central nervous system of the adult as well as for that 

 of the older foetuses. When successful, it possesses two advan- 

 tages over the first modification : ( i ) It obviates the necessity 

 for fresh material whenever it is found desirable to use the 

 method. The material may be preserved indefinitely in 10 per 

 cent, formalin, and in large quantities, from which small pieces 

 may be taken as occasion requires. (2) It gives a much greater 

 amount of contrast. The black-stained neurone or neuroglia 

 cell lies in an almost white field. The material once preserved 

 in formalin, this application is fully as rapid as the first. Well- 

 stained cells of the spinal cord and of the cerebral cortex have 

 been obtained by it in 48 hours after removal from the formalin. 



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