386 ANNALS NEW YORK ACADEMY OF SCIENCES 



The experiments relate to the reduction of selenium compounds by chem- 

 ical substances of biologic significance, by micro-organisms, by plant sub- 

 stances and by animal tissues. Toxicological and pharmacological effects 

 were also studied, as well as the effect on germination and growth of 

 plants, the effect on enzyme activity and the effect on the precipitation 

 of proteins. The compounds employed were selenium dioxid (selenious 

 acid), sodium hydrogen selenite, normal sodium selenite, selenic acid, 

 sodium selenate, potassium selenocyanate. For some of the compounds 

 thanks are due to Professor Victor Lehner, of the University of Wisconsin. 



Sodium Selenite as a Eeagent for Eeducing Substances 



Sodium selenite in alkaline solution can be used as an indicator for 

 reducing substances, especially for the carbohydrates containing a free 

 carbonyl group. The following do not reduce sodium selenite (alkaline 

 to litmus) : acetone, formaldehyde, trioxymethylene, acetaldehyde, furol, 

 benzaldehyde, cinnamic aldehyde, salicyl aldehyde, piperonal, meth}^ al- 

 cohol, ethyl alcohol, glycerol, erythrol, mannite, inosite, phenol, the^ 

 cresols, thymol, a-naphthol, acetic acid, butyric acid, /?-oxybutyric acid, 

 palmitic acid, stearic acid, trichloracetic acid, oxalic acid, tartaric acid, 

 citric acid, oleic acid, malic acid, cinnamic acid, hippuric acid, glycocol, 

 alanin, guanidin carbonate, leucin, urea, thio-urea, ammonium sulfo- 

 cyanid, caffein, theobromin, uric acid, sodium urate, creatinin, lecithin, 

 cholesterol, palmitin, stearin, olein, blood albumen, blood fibrin, edestin, 

 egg albumen, gelatin, peptone, proteoses, ovalbumin, collagen, osseo- 

 mucoid, elastin, saccharin, antipyrin, anthraquinone, sucrose, raffinose, 

 cellulose, starch, dextrin, glycogen, inulin, esculin, amygdalin, and the 

 following gums : arabic, tragacanth, guaiac, rosin, benzoin, kino, aloes, 

 asafoetida, myrrh, gambir. Alcoholic solutions of benzoin, kino or aloes 

 give a red-brown to cherry-red solution without the addition of sodium 

 selenite. The following reduce sodium selenite : amidol, arabinose, rham- 

 nose, xylose, dextrose, galactose, levulose, maltose, lactose, liydroquinone, 

 phloroglucin, pyrogallol, hydroxylamin hydrochlorid, phenylhydrazin h}^- 

 drochlorid, benzidin hydrochlorid, hydrazin hydrate; arsenious, hydro- 

 bromic, hydriodic, phosphorous, hypophosphorous and sulfurous acids ; 

 ferrous sulfate, stannous chlorid, zinc and hydrochloric acid, hydrogen 

 sulfid, acetylene, formic acid, gallic acid, lactic acid, tannic acid. 



Acetone, acetaldehyde, formaldehyde, aceto acetic ester, yS-oxybutyric 

 acid, creatinin, lactic acid, formic acid and inulin reduce in acid but not 

 in alkaline mixtures of sodium selenite. Methyl alcohol and ethyl alcohol 

 reduce sodium selenite strongly acidified with sulfuric or with hydro- 



