30 Neurological Technique 



or in loose chemical combination, and the subsequent treatment 

 is modified by the amount of this extraction. For sections from 

 the same block even the propitious moments are found more or 

 less by chance. 



In sections which appear pale blue with very little or no 

 violet at the end of 2 minutes in the 96 per cent, alcohol, the 

 staining may be improved to some extent by using either a weak 

 solution (2 per cent.) of ammonium molybdate instead of the 

 water as in step i 5 (c), or by using a stronger solution of the 

 toluidin blue. But results obtained from such material are gen- 

 erally poor. 



Cells rich in fibrillae take longer in differentiating than cells 

 poor in fibrillae. For this reason sections of the spinal cord take 

 longer than sections from the cerebral cortex, for example. 



Mount slides enough to allow considerable experimentation. 



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