342 THE AMERICAN MONTHLY [Nov., 



of Leipzig (100c. c. saturated aqueous solution of Orange, 

 20 c. c. saturated aqueous solution of Acid fuchsin, 50 c. 

 c. sat. aq. sol. Methyl Green. ) was diluted 60 times and 

 the section allowed to stain 2 or 3 hours, then washed 

 and dehydrated with 95 per cent of alcohol, cleared in 

 zylol or carbol-xylol (Carbolic acid crystals 1 part, xylol 

 3 parts) and mounted in xylol balsam. It is necessary 

 that the alcohol with which the stain is washed out, be 

 neutral as, if acid, the methyl green is washed out, and 

 if alkaline the fuchsin is faded in the result. Tissue 

 hardened in mercuric chloride solution, or with picric al- 

 cohol may be stained with this with good results. It 

 was employed however only with tissue cut in paraflBne, 

 since the readiness with which collodion was stained by 

 the methyl green rendered it less satisfactory when that 

 method of imbedding was employed. 



Microscopical Technique Applied to Histology. — VIIL 



[PROM THE FRENCH OF RENE BONEVAI..] 



(Continued from page 318.) 

 THE PERIPHERAL NERVES. 



Dissociation. — It is by dissociation that the study of the 

 elements entering into the composition of the nerves 

 should be begun. We select two, the one of nerve fibres 

 with myeline, the other of fibres without myeline, or 

 those of Remack. 



The frog's sciatic is formed of a single nervous bundle 

 which bifurcates at the lower extremity. This arrange- 

 ment renders dissociation especially easy, and it is the 

 nerve to be chosen for the study of isolated nerve tubes. 

 After destroying the frog's spinal chord by the aid of a 

 needle slipped into the spinal canal, skin the animal and 

 lay it on its belly. The femoral triceps above and the 

 semi- membranous below define a space which points out 

 the position of the sciatic nerve. Carefully removing 



