104 THE ALUMNI JOURNAL 



NEW REACTION FOR CHOLESTERIN AND 

 OXYCHOLESTERIN. 



L. Golodetz {Phartn. Post, xlii, p. 309) states that the majority of 

 the reactions for cholesterin are not applicable under the microscope. 

 The only reaction that may be so applied is that using concentrated 

 sulphuric acid and a trace of iodine, whereby the cholesterin is colored 

 first violet, then blue, green, and finally red. Sulphuric acid, however, 

 colors quite a number of organic compounds, as is vi^ell known; hence 

 its use for detecting cholesterin in mixtures is apt to mislead. For 

 this reason the author has employed a mixture of 5 parts concentrated 

 sulphuric acid and 3 parts aqueous formaldehyde. This mixture im- 

 parts a blackbrown color to cholesterin, which is specific of the latter. 

 Under the microscope the color appears somewhat lighter, with a tinge 

 of orange. With this mixture may be readily detected the smallest, 

 the still microscopically observable, articles of cholesterin, even in 

 mixtures with other substances, without .in any way having occasion 

 to fear any by effect of the sulphuric acid. 



The author at the same time reports on a modification of Tschuga- 

 jew's trichloracetic acid test for cholesterin. In this modification the 

 substance under examination is brought into contact with a drop of 

 liquefied trichloracetic acid, and a drop of a 30-per cent, formaldehyde 

 solution is then added. If cholesterin is present, a deep blue color- 

 ation develops. Oxycholesterin is colored green by trichoracetic 

 acid, and its spectrurn exhibits a dark band in the red. 



J. Lifschiitz also reports on a new color reaction for cholesterin. The 

 reaction, together with the characteristic absorption spectra afforded, 

 and which marks the first neutral oxidation stage of cholesterin in 

 glacial acetic acid on the addition of concentrated sulphuric acid, is 

 excellently adapted for the recognition of cholesterin. He recom- 

 mends, as the most suitable oxidizers, the peroxides of the organic 

 acids. The simplest mode of making the test is as follows: A few 

 milligrammes of cholesterin are dissolved in 2—3 Cc. glacial acetic 

 acid, a few granules of benzoyl peroxide added, and the whole boiled 

 up once or twice. In the solution, when cold, 4 drops of concentrated 

 sulphuric acid are allowed to fall; on collecting at the bottom of the 

 testtube, these drops immediately acquire a bluish-violet or bluish- 

 green color. On shaking, the mixture rapidly becomes colored either 

 violet-red followed by a fine blue, violet by transmitted lamp light, 

 and changing to a pure green on several hours' standing; or on 



