CHEMISTRY. 539 



former loss is especially great with alkaline urine which contains a large proportion 

 of preformed ammonia. 



The authors recommend as the most satisfactory procedure for urine combustions 

 the direct evaporation of the urine in a platinum capsule to be used in the bomb, 

 employing a sufficient amount of urine to produce 1 to 1.5 calories when burned. 

 This should be evaporated in a vacuum at ordinary temperature without the use of 

 a cellulose block or any additional substance. Methods of introducing corrections 

 for the energy on the basis of the loss of nitrogen are discussed. 



Determination of sulphur and phosphoric acid in foods, feces, and urine, 

 J. A. LeClerc and W. L. Dubois {Jour Amir. Chem. Soc, 26 (1904), No. 9, pp. 1108- 

 1113). — Comparisons of Berthelot's calorimetric, Parr's calorimetric, and Osborne's 

 sodium peroxid methods for sulphur. The Osborne method was found the most 

 satisfactory and reliable. 



The identification of corn meal in bread, D. Ottolenghi (Ztschr. Untersuch. 

 Nahr. u. Genussmtl., 8 (1904), No. 3, pp. 189-193). — In the method described dried 

 bread is treated with potassium-hydroxid solution, filtered, evaporated to dryness, 

 and extracted with boiling isoamylalcohol for several hours. If the bread is free 

 from maize flour the resulting yellow-brown liquid when filtered is clear or slightly 

 opalescent. If the bread contains maize meal, however, it is more or less opaque. 

 When the cold liquid is filtered the addition of benzol crystals causes more or less 

 opalescence if maize is present, otherwise it remains clear. Other differences are 

 pointed out and the method is described in detail. 



The gravimetric estimation of boric acid by perforation with ether, A. 

 Partheil and J. A. Rose (Arch. Pharm., 242 (1904), Nos. 6, pp. 478-480; 7, pp. 481- 

 488). — The method recommended consists in general in incinerating the material, 

 extracting the borate from the ash with ether, evaporating to dryness, and weighing. 

 In the case of oleomargarine an aqueous extract is evaporated to dryness, incinerated, 

 and treated with ether. 



The estimation of boric acid as phosphate, F. Milius and A. Meusser 

 (Ber. Deut. Chem. Gesell, 37 (1904), pp. 397-401; abs. in Ztschr. Untersuch. Nahr. n. 

 Genussmtl., 8 (1904), No. 3, pp. 222, 223). — A study of the estimation of boric acid 

 as boryl phosphate. 



The influence of hydrogen peroxid on enzyms, A. J. J. Vaxdevelde (Beitr. 

 Chem. Physiol, u. Pathol., 5 (1904), No. 11-12, pp. 558-570). — Hydrogen peroxid 

 increased the action of rennet, pepsin, trypsin, and the proteolytic ferment of milk, 

 the increase being proportional to the concentration of the reagent. The increased 

 activity was noticeable in the swelling of the material treated, as well as in the rapid- 

 ity of solution. Variations in the effect of the reagent on the different ferments 

 studied are discussed. 



Tables for chemical calculations, H. L. Wells (New York: Henry Holt & Co., 

 1904, pp. 60). 



A new apparatus for preparing hydrogen sulphid, carbon dioxid, or hydro- 

 gen, H. Arzberger (Osterr. Chem. Ztg., 7 (1904), No. 21, pp. 489, 490). 



The use of electricity in laboratory operations, W. Zielstorff ( Chem. Ztg., 28 

 (1904), No. 86, pp. 1026-1028). — Devices in which electric currents are used for heat- 

 ing extraction apparatus, propelling shaking machines, and heating drying ovens are 

 described. 



Yearbook of chemistry, R. Meyer et al. (Jahrb. Chem., 13 (1903), j>j>. XII4- 

 600). — This is a biographical and bibliographical review of the more important 

 advances in pure and applied chemistry during the year 1903. 



Extracts from the proceedings of the Association of Official Agricultural 

 Chemists, 1904, edited by H. W. Wiley ( U. S. De})t. Ayr., Bureau of CJiemistry 

 ( 'in: 20, pp. 19). — This contains reports of committeeson recommendations of referees 

 of the association and the action taken by the association upon these recommenda- 



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