July 9, 1915] 



SCIENCE 



69 



nitrogen of the soil, but there are decided differ- 

 ences in individual cases. Cropped soils produce 

 less nitric nitrogen than the same soil uneropped. 

 Addition of calcium carbonate diminishes the in- 

 dividual variation, but does not eliminate it. 



C. B. LiPMAN: The Form of Nitrogen in Nitro- 

 genous Materials as an Index to Nitrifiatility. 

 M. X. Sullivan: The Formation of Creatinine hy 



Whatever work has been done on the formation 

 of creatinine by bacteria has been on media con- 

 taining peptone. Peptone, however, is of animal 

 origin and in itself contains antecedent bodies of 

 creatinine and on slight hydrolysis with acid read- 

 ily gives creatinine. In the present experiments 

 it was found that a trace of soil added to a pro- 

 tein-free synthetic culture medium, with ammonium 

 sulphate the source of nitrogen led to the develop- 

 ment of a strong growth of bacteria. On analysis 

 six months after inoculation of the media with 

 the soil, creatinine was found by color reactions 

 and by the formation of creatinine zinc chloride. 

 M. X. Sullivan: The Amount of Creatinine in 



Plants. 



Several years ago the writer found that creati- 

 nine, as judged by color reactions and the forma- 

 tion of creatinine zinc chloride, occurred in plants. 

 In the present work the quantity of creatinine was 

 determined by Folin's eolorimetric method. The 

 determinations were made on the water-soluble 

 part of the alcohol extract, after treatment with 

 lead acetate, evaporation in vacuo, and taking up 

 in absolute alcohol. ' Only a few parts per million 

 (1-6) were found in the ungerminated seed of 

 wheat and soy bean. The amount of creatine in- 

 creased during germination. In wheat seedlings 

 10 to 12 days old from 40 to 65 parts per million 

 of creatinine were found. 

 Edward Gudeman: Toilet Papers, a Source of 



Infection. 

 Adolph Bernhard : A Simple Colorimetric Method 



for the Determination of Free Beducing Sugars 



and Total Carbohydrate in Miscellaneous Food 



Products. 



The colorimetric method recently suggested by 

 Lewis and Benedict for the sugar in the blood has 

 been successfully employed, in slightly modified 

 form, for the estimation of free reducing sugars 

 in fruits, milk and a variety of food products. 

 The method has also been utilized for the determi- 

 nation of the total carbohydrate in feces, tissues 

 (glycogen) and in various food stuffs, especially 

 diabetic foods. 



For the determination of the free reducing 

 sugars in fruit, a sample of the moist fruit is ac- 

 curately weighed, ground in a mortar, made up to 

 some convenient volume with water, and then sufd- 

 eient dry picric acid added to make a saturated 

 solution, precipitate traces of protein, etc. Two 

 c.c. of the filtrate are now heated with 3 c.c. of 20 

 per cent, sodium carbonate for 10 minutes, diluted 

 to 10 c.c. and compared with a standardized pic- 

 ramic acid solution. The total carbohydrate is 

 similarly determined after hydrolysis and neutra- 

 lization, the results showing excellent agreement 

 with those obtained by the AUihn method. 

 James P. Atkinson: The Seducing Action of Dis- 

 tillates from Certain Carbohydrates on Distilla- 

 tion with Steam and from Alhaline Solution. 

 An alkaline solution, containing glucose, under 

 the conditions imposed in water analysis gave a 

 greenish yellow color in the Nessler reagent, in- 

 creasing in depth until precipitation of the 

 reagent occurred. S. and S. filter paper No. 589, 

 the purest samples purchasable of saccharose, lac- 

 tose, grape sugar, levulose, maltose, mannose, dex- 

 trin, and soluble starch, similarly treated in water 

 free from ammonia, or in presence of sodium car- 

 bonate, gave a yellow color with Nessler reagent, 

 and, finally, in all cases except saccharose, reduced 

 the reagent to metallic mercury. Evidently, the 

 presence of carbohydrate may be confused with 

 the presence of ammonia indicated by the Nessler 

 reagent. In water analysis, in urine and in blood 

 tests this fact should be regarded. 



Sajra Stowel Graves: A Precipitant for Am- 

 monia. 



A reagent consisting of 130 c.c. of water, 80 g. 

 of sodium chloride, 100 c.c. cold saturated mer- 

 curic chloride and 70 c.c. of cold saturated solu- 

 tion of lithium carbonate, was found as sensitive 

 as Nessler 's reagent. With the nephelometer this 

 reagent was found to show ammonia in ammonium 

 sulphate solutions as dilute as 0.00001 per cent. 

 Soluble starch, prepared by boiling 1 g. of starch 

 until clear, then diluting to 100 c.c, held the pre- 

 cipitate in suspension the ten to thirty minutes 

 necessary in nephelometric readings. Tests were 

 made on a standard ammonium sulphate solution, 

 made according to Folin's directions. The solu- 

 tion was found to give satisfactory results with 

 ammonium sulphate alone, with ammonium sul- 

 phate in presence of filter paper, with urie acid, 

 and with urine, in water analysis, in normal and 

 micro Kjeldahl determinations. This new reagent 

 for ammonia is as sensitive as Nessler 's reagent 



