October 7, 1910] 



SCIENCE 



477 



of cowpea hay is only slightly soluble in water, 

 but approximately 40 per cent, of the ether ex- 

 tract of the excrement is easily soluble in water. 

 Full details and conclusions will be published 

 elsewhere. 

 Determination of Ammonia 'Nitrogen in Water in 



the Presence of Hydrogen Sulphide: E. Bartow 



and B. H. Haerison. 



To the water containing hydrogen sulphide 

 50 CO. of normal sulphuric acid was added and 

 100 c.c. of water distilled over. 50 c.c. of normal 

 sodium hydroxide was then added ?.nd ammonia 

 determined by distillation and nesslerization. 

 The hydrogen sulphide did not interfere with the 

 ammonia determination and the addition of sul- 

 phuric acid was shown to have no appreciable 

 efl'ect on the regular determination of free and 

 albuminoid ammonia. 

 Extent and Composition of the Incrustation on 



Filter Sands: E. Bartow and C. E. Millar. 



Examinations were made of sand from five 

 water purification plants in Illinois which use 

 lime and sulphate of iron as a coagulent. By 

 means of acid from 13 to~ 84 per cent, of incrusta- 

 tion was dissolved. This is equivalent to an 

 increase of from 16 to 650 per cent, in the weight 

 of the original sand. As the amount of sand in 

 the beds was not increased, an amount of sand 

 equal to the soluble matter has passed into the 

 sewer. The soluble matter consisted of from 86 

 to 96.5 per cent. CaCoj. 

 Sigh Protein Bread: J. A. LeClerc and B. R. 



Jacobs. 



The results of baking tests show that a well- 

 piled loaf, of fair size, attractive in appearance, 

 and palatable, can be made out of 25 per cent, 

 cotton-seed flour and 75 per cent, ordinary flour. 

 The protein content of such cotton-seed bread is 

 over 14 per cent., while of bread made from ordi- 

 nary flour it is under 9 per cent. 



A Note on the Eypoxanthine of Meat: C. B. 



Bennett. 



When fresh rabbit meat, or meat coagulated by 

 heating to 75° C, is extracted with water and 

 the filtrate treated with barium hydroxide and 

 basic lead acetate, almost no hypoxanthine is 

 obtained in the final filtrate. Meat left standing 

 in a chamber of ether, or in water for a few days, 

 and then subjected to like treatment, gives much 

 more hypoxanthine. It is concluded that hypo- 

 xanthine is in a combined st^te in fresh meat and 

 is liberated on standing raw, but that heating 

 almost stops this action. 



On the VnificaUon of Soil Analysis: E. W. HiL- 



gard. 



This paper, while insisting strongly upon the 

 practical need of soil analysis for the determina- 

 tion of permanent soil values, deplores the lack 

 of uniformity in the method of preparing the soil 

 extract, whereby comparisons are rendered diffi- 

 cult or impossible, and an enormous amount of 

 work is wasted. In view of the hopelessness of 

 any international agreement upon arbitrary pre- 

 scriptions, the adoption of a natural limit of 

 extraction, by the action of strong acids — prefer- 

 ably hydrochloric — is recommended; according to 

 the author's experience, the results of such an- 

 alyses lend themselves to practical interpretation 

 at least as readily as those by any other method. 

 Quantitative Chemical Analysis of Animal Tissue 



— v., Estimation of Chlorine: W. Koch. 



The estimation of chlorine, either by analysis 

 of the total ash or by direct water extraction in 

 tissues rich in lipoids such as the brain or liver, 

 can hardly be said to yield results of any degree 

 of accuracy. In the ash the chlorides are often 

 replaced by sulphates or phosphates derived from 

 the burning of organic combinations of these ele- 

 ments. A watery extract of a tissue like the 

 brain can only be filtered with the greatest diffi- 

 culty and the complete extraction would be almost 

 impossible. 



In connection with the methods previously out- 

 lined under the above general title it was found 

 that the chlorides all pass into the fraction 2 or 

 the alcohol soluble fraction. By precipitating the 

 lipoids in this fraction without chloroform and 

 with nitric instead of hydrochloric acid a solu- 

 tion is obtained in which the chlorides can be 

 titrated direct by Volhard's method. Tlie estima- 

 tion of chlorine can be thus combined with that 

 of any other tissue constituent described in these 

 methods. Some results obtained on the brain are 

 given below: 



Whole Brain Corpii$\ CaUosum 



In per In per In per In per 



cent, of cent, of cent, of cent, of 



moist dry moist dry 



tissue tissue tissue tissue 



Case 74 0.20 0.89 — r- 



Case 75 0.16 0.71 0.15 0.48 



A Convenient Drying Oven: M. M. MacLean. 



An oven for small laboratories made of two 

 thicknesses of thin sheet iron with asbestos board 

 between; heated by incandescent lamps, the tem- 

 perature controlled very accurately by thermostat 

 device. 



