1917] AGEICULTURAL CHEMISTRY — AGROTECHNY. 313 



The cause of the slight discrepancies between the laboratory experiments autl 

 the theoretical results calculated from the equations is discussed. The methods 

 of analysis used are deemed to be adequate in scope and accuracy, and also to 

 be practical. Any loss is considered to arise chiefly during manipulation of the 

 solutions through oxidation, and could be eliminated only by manipulating in an 

 atmosphere of some inert gas. 



A formula for preparing an animal dip in which 8 lbs. of quicklime, 18 lbs. 

 of sulphur, and somewhat more than 10 gal. of water are boiled for one hour 

 is submitted. 



The arsenates of lead, I, C. C. McDonnell and C. M. Smith {Jour. Amer. 

 Chem. Soc, 38 {1916), No. 10, pp. 2027-2038).— Mono-lead arsenate (PbH* 

 (AsOi)!) was prepared, and its physical and chemical properties are described. 

 The methods of preparing crystalline di-lead arsenate (PbHAs04) are reviewed, 

 and its physical and chemical properties fully described. Crystallized tri-lead 

 arsenate, lead metarsenate, and di-lead pyroarsenate were also prepared and 

 their physical and chemical properties noted. 



Lead arsenates. — A study of the factors controlling the reactions of lead 

 nitrate and lead acetate with disodium arsenate, G. E. Smith {Jour. Amer. 

 Chem. Soc, 38 {1916), No. 10, pp. 2014-2027).— From a study at the Montana 

 Experiment Station of the factors controlling the reactions of lead nitrate and 

 lead acetate with disodium arsenate, the author concludes that " the lead arse- 

 nates produced are mixtures of diplumbic arsenate (PbHAs04) and lead hydroxy- 

 arsenate (PbBOH(As04)3). The products of the reactions at low temperatures, 

 when the reactions have come to an equilibrium, whether lead acetate or lead 

 nitrate is used consist principally of diplumbic arsenate. The products of the 

 reactions at infinite dilutions (less than 1/1,000-molar), whether lead acetate 

 or lead nitrate is used, consist principally of lead hydroxyarsenate if the pre- 

 cipitates are filtered immediately after the precipitation. The precipitate that 

 is first formed is lead hydroxyarsenate; diplumbic arsenate is produced by a 

 secondary reaction." 



With an increase of alkaline disodium arsenate greater amounts of lead 

 hydroxyarsenate are produced. As the concentration increases the relative 

 amount of diplumbic arsenate increases. With an increase in temperature 

 more of the hydroxyarsenate is formed. 



The procedures used for the preparation of the pure reagents and the ma- 

 terials studied are described in detail. 



Researches on organic periodids. — II, Periodids of antipyrin, iodoanti- 

 P3rrin, and pyramidone, W. O. Emery and S. Palkin {Jour. Amer. Chem. Soc., 

 88 {1916), No. 10, pp. 2166-2181).— A continuation of previous work (E. S. K., 

 34, p. 502). 



Preparation of bromoacetylglucose and certain other bromoacetyl sugars, 

 J. K. Dale {Jour. Amer. Chem. Soc., 38 {1916), No. 10, pp. 2187, 2188). 



Condensation of thiobarbituric acid with aromatic aldehydes, A. W. Dox 

 and G. P. Plaisance {Jour. Amer. Chem. Soc, 38 {1916), No. 10, pp. 2164- 

 2166). — In the course of a study at the Iowa Experiment Station on the re- 

 action between aromatic aldehydes and the methylene group of the ureids of 

 malonic acid, a number of condensation products were prepared and ai-e 

 described. 



Concerning certain aromatic constituents of urine, R. J. Anderson {New 

 New York State Sta. Tech. Bui. 55 {1916), pp. 3-25; Jour. Biol. Chem., 26 {1916), 

 No. 2, pp. 387-415).— This bulletin reports the following studies: 



I. The nonphenolic volatile oils of cotv urine. — The author has shown that 

 the so-called neutral oil obtained from cow urine consists for the greater part 



