172 THE AMERICAN MONTHLY [June, 



principal planes of optical electricity may be found, the 

 positions of the optic axes ascertained, and the true in- 

 ternal angle of the latter measured. One of the most 

 important advantages of the method is the simplification 

 which it introduces into the study of triclinic crystals, 

 hitherto almost dreaded by the crystallographer for the 

 trouble they involve. It would appear that their oftti- 

 cal investigation by the immersion method offers but 

 slightly more difficulty than that of crystals of higher 

 symetry, the positions of the optic axes being readily 

 found and the true angle at once afforded. This alone 

 would entitle Prof. Klein to the thanks of crystallog- 

 raphers and mineralogists for perfecting so admirable 

 an aid to investigation. 



A Description of a Simple and Reliable Method to Trace 

 the Nerves in the Muscle. 



By CHR. SIHLER, M. D., 

 cleveland, ohio. 



The process employed in this method consists of three 

 parts : 



1. The fresh muscle is treated with a macerating fluid, 

 which partly dissolves, partly softens, the connective 

 tissue, substances between the muscle, and nerve-fibres, 

 allowing the staining fluid free access to the tissue ele- 

 ments, which it is the object of the staining fluid to 

 penetrate and to make demonstrable. 



2. The softened and loosened muscle-bundles of 

 sufficiently small size are stained in dilute Bhrlich's 

 ha^matoxyline. 



3. Overstaining generally taking place, the stained 

 muscle-bundles are treated with dilute acetic acid until 

 the nerves and nerve-endings show up distinctly. 



The maceration fluid (a) has the following composition : 



