1900.] On the Myelins, etc., of the Organism. 



361 



find, exhibit marked myelin formation), it is obvious from the descriptions 

 given of the microchemical characters, either that there are several bodies 

 possessing myelin properties, or, if only one body, that then it exists in very 

 varying degrees of purity, for the reaction with osmic acid varies, as does 

 that with dyes such as Sudan III, neutral red, saffranin and methylene blue. 

 In one and the same specimen these reactions may vary. 



A very characteristic property of a large number of myelin bodies (shown, 

 we find, very imperfectly by the autolytic group, at least in the early stages 

 of autolysis) is that of double refraction. If a section or some of the 

 expressed juice of the suprarenal be taken, what under the ordinary microscope 

 appear to be minute fatty globules are seen in part to exhibit double 

 refraction under polarised light. Between the crossed ISTicol's prisms each 

 little globule exhibits a black cross with four highly illuminated, bright 

 and colourless intervening sectors. This property was first observed by 

 Mettenheimer in 1858, rediscovered by Apathy for nerve myelin in 1890, 

 by Miiller and Schmidt in 1898 for sputum myelin and again, independently, 

 by Kaiser ling and Orgler for suprarenal myelin in 1902. The question 

 whether the presence of doubly refracting myelin globules in atheromatous 

 vessels as noted by Torhorst in the laboratory of Aschoff could be reconciled 

 with Klotz's detection in Adami's laboratory of compound soaps in the same 

 areas led to the present investigation. 



The following bodies gave negative results : pure fatty acids, the glycerides 

 of fatty acids (neutral fats), pure lecithin,* pure protagon, cholesterin, sodium, 

 potassium and calcium stearates and palmitates, spermin plus oleic acid. 

 Under no conditions of heating or employing various menstrua could we with 

 these obtain doubly refracting globules. 



The following bodies gave positive results : the oleates of sodium 

 potassium, ammonium and calcium ; the stearate and palmitate of 

 ammonium ; cholesteryl oleate, palmitate, stearate, and butyrate (obtained 

 by heating together cholesterin and one or other fatty acid), lecithin plus 

 cholesterin (? cholesteryl lecithate) ; cholin oleate ; lecithin acted upon by 

 ammonia, caustic potash, and caustic soda. With all these substances by 

 one or other means it was possible to gain perfect small spherules, highly 

 refractive, affording the characteristic cross when examined between Nicol's 

 prisms. 



It was clear, therefore, that, inter alia, certain bodies of the nature of soaps 

 afford this particvdar reaction. But at the same time, with not a few of these 

 bodies, notably the simple soaps and the lecithin compounds with which the 



* The form employed was Riedel's lecithol : the so-called pure lecithin from egg yolk 

 contains abundant cholesterin. 



