GRANULES AND FAT OF STRIATED MUSCLE 25 



4. Results with the methods of Weigert, Altmann, Benda and 

 Regaud. To demonstrate the true interstitial granules, Altmann 

 ('94) employed his bichromate-osmic acid-fuchsin method. 

 Holmgren ('10) made use of Bend's mitochondrial method and 

 Regaud ('09) used his formalin-bichromate iron-hematoxylin 

 method. I find that the granules may be demonstrated in a 

 satisfactory manner by any of the above methods as well as by 

 the Weigert method which involves formalin-bichromate fixa- 

 tion followed by hematoxylin staining. Similar results by these 

 methods is to be expected for the methods are chemically similar 

 although the stains employed, acid fuchsin, Crystallviolett, 

 hematoxylin, and iron-hematoxylin, are of a varied character. 



Smith, Mair and Thorp ('08) have explained the chemistry of 

 the Weigert hematoxylin process. They found that the method 

 depends upon the oxidizing action of potassium bichromate upon 

 unsaturated fats. The oxide of chromium forms with the fat 

 molecules a compound which is insoluble in fat solvents and 

 capable of forming a lake with hematoxylin. It is only during 

 the process of oxidation that the fat-chrome compound forms 

 the hematoxylin lake. After complete oxidation the staining 

 no longer takes place. These observers found the method ap- 

 plicable not only to unsaturated fats, as oleic acid and triolein, 

 but also to lipoids in which unsaturated groupings occur such 

 as cholesterin and cerebrosides. The work of Smith, Mair, and 

 Thorp was confirmed and extended by Faure-Fremiet, Mayer, 

 and Schaeffer ('10). They found that not only the unsatur- 

 ated but also certain of the saturated fatty acids, including 

 palmitic, are rendered insoluble in alcohol and xylol by oxidizing 

 reagents and also by the action of salts of the heavy metals. 

 (Benda explained the action of the salts of copper on fatty 

 acids as dependmg upon the formation of insoluble copper 

 soaps.) These insolubilized fats were stained with more or less 

 intensity by both acid and basic anilin dyes and in certain cases 

 (after copper or chromic compounds, salts of iron and of zinc) 

 a hematoxylin lake was formed. The phosphatid lipoids were 

 not rendered insoluble in xylol by the action of salts of the 

 heavy metals, but were insoluble after chromic and certain other 



