1915] Edgar G. Miller, Jr. 219 



In Order to test the influence of acidity, or alkalinity, upon the 

 reduction of sodium selenite, nineteen reagents were prepared. One 

 consisted of sodium selenite neutralized with sulfuric acid. Ten 

 were alkalin, the basicity being due to sodium selenite per se, to so- 

 dium bicarbonate, sodium carbonate, sodium tetraborate, sodium Sili- 

 cate, sodium hydroxid, di-sodium hydrogen phosphate, potassium 

 hydroxid and Rochelle salt, or sodium carbonate and sodium citrate. 

 Eight reagents were acidified by the addition of one of the follow- 

 ing: potassium bi-sulfate, sodium di-hydrogen phosphate; hydro- 

 chloric, nitric, sulfuric, phosphoric, citric, or tartaric acid. When 

 these reagents were heated none reduced, even with complete evapo- 

 ration, except those containing citric or tartaric acid. These two 

 reagents deteriorated after standing several months. 



Experiments with the above-named reagents were conducted at 

 37.5° C. Solutions (0.5 percent) of arabinose, rhamnose, xylose, 

 glucose, fructose, galactose, sucrose, maitose, lactose, glycogen, 

 starch, dextrin, inulin, raffinose ; mucic, lactic and f ormic acids ; ace- 

 tone, and formaldehyde, were tested. Three cc. of the sol. to be 

 used were mixed with 2 cc. of the selenite reagent and toluene added. 

 The tubes were kept at 37.5° C, and examined from time to time. 

 Controls were run with Fehling and Fehling-Benedict reagents. 

 The reagents containing sodium hydroxid and potassium hydroxid 

 (selenite and Fehling) were the first to show reduction. Fehling 

 reagent reduced more quickly than Fehling-Benedict. Glycogen, 

 starch, dextrin, inulin and raffinose reduce acidified Solutions of so- 

 dium selenite by the end of 4 days. Alkalin sol. were not affected. 

 Formic acid, lactic acid, and formaldehyde reduce in acid sol. only. 

 Acetone profusely reduces acid sol.; very faintly, some of the alka- 

 lin sol. The reagent, acidified with nitric acid, showed no reduction, 

 except in the case of acetone. Neutralized sodium selenite is a very 

 ineffective indicator of reduction. The presence of sodium tetra- 

 borate inhibits to a very striking extent the reduction of sodium 

 selenite. 



A sol. containing 2 percent of sodium selenite, 10 percent of sodi- 

 um citrate, and 10 percent of sodium carbonate, has been tested with 

 reducing sugars ( 100° C). Reduction with this reagent takes place 

 in one minute, or even less. At first a deep chlorin-yellow color is 

 developed. After standing a minute or two, this color gives way to 



