i!'i9] AGRICULTURAL < lll.MISTRY — AGROTECHNY. 505 



Course of reaction in explosions of dilute CS-air mixtures, <;. R. Stewast 

 and 3, S. Burd {.lour, Indus. <n\<i Etiffin. Chem., li {1919), No. ..'. /</*. tSO-188).— 

 This is the report of ;i laboratory study of the combination products of carbon 

 bisulphid, made a1 the California Experiment Station In connection with In- 

 vestigations on the control of ground squirrels l>y fumigation methods (B. 8. K., 

 40, p. 860). 



0ombu8tlon of carbon bisulphid In dilute mixtures with air was found to 

 result always in the formation of carbon dloxld, carbon monoxld, sulphur 

 dlozld, and Borne residual carbon bisulphid. The character of the resulting 

 gas mixture, quantital ively considered, was found to depend more upon the 

 initial carbon bisulphid concentration than upon variation In the reaction. 



Color in relation to chemical constitution. E. R, Watson (Neto York and 

 London: Longman*, Qreen & Co., mis. pp. XII+197, pis, t5, figs. 52)— In Ibis 

 volume, which Is one of the monographs on Industrial chemistry edited by E. 

 Thorpe, an attempt has been made to give a brief and connected account of the 

 main lines on which research and discussion have taken place with regard to 

 the relation between color and chemical constitution and the principal theories 

 which have been proposed as to the nature of the vibrations to which ordinary 

 color is due. An extensive bibliography is appended. 



Laboratory apparatus for rapid evaporation, E. C. fcfEBRlLL and C. O. 

 Ewing [Jour. Indus, and Engin. ("hem., n {J010), No. .<?, pp. 2A0, fig. I). — The 

 apparatus, devised by the authors at the Bureau of Chemistry of the U. S. De- 

 partment of Agriculture, employs air from a blast which is first passed through 

 n screw-capped brass cylinder, packed With cotton, which filters out any particle 

 that might contaminate the residue dUrlng the operation, and then thrOugb a 

 L'-m. coil of 0.6 cm. copper tubing which rests on the steam pipes in an ordinary 

 steam hath. This is connected with individual blowers supported over the 

 respective holes In the steam hath and provided with glass stopcocks, so that as 

 many as are desired can be used simultaneously. 



The apparatus is said to be specially useful for the rapid top evaporation of 

 solutions which are apt to decrepitate. By insulating the beaker from the 

 bath, a rapid evaporation at a low temperature can be made of solutions of 

 materials which are apt to volatilize, polymerize, or decompose at higher tem- 

 peratures. 



An improved automatic burette. (}. J. SotTQH (Jour. Indus, and Engin. 

 Chew.. 11 ( t919), No. S, p. 229, flg. 1).— The author at the Bureau of Soils of the 

 U. S. Department Of Agriculture has devised an automatic burette, the princi- 

 pal merits of which are said to be that it requires no bracket or support to 

 hold it in the solution reservoir and that it can be cleaned quickly and used 

 for some other solution. The base of the burette consists of a tube sur- 

 rounded by a much larger tube, which tits into the rubber stopper of the solu- 

 tion reservoir. This outer Jacket Is connected with a T-shaped tube, to one 

 outlet of which is attached a rubber pressure hulb. The other outlet is closed 

 by the timrer when pumping air into the reservoir. A hole in the outer jacket 

 serves t<> equalize the pressure in the reservoir. 



A diagram is given of the apparatus, with accompanying dimensions. 



Colorimetric scale for the rapid estimation of free hydrochloric acid by 

 means of a solution of brilliant green, M. Dexort and RoCHX (Compt. Rend. 

 Sor. Blot. [Paris], SI [1918), No. 12. pp. G!,G-6!,9; abs. in Jour. Chem. Soc. 

 [London], ii) (1918), No. 674, IF, p. 1,50).— The scale is prepared by mixing In 

 varying proportions a nontiltered 1 per cent hydro-alcoholic solution of methy- 

 lene blue, a tittered " per cent aqueous solution of neutral potassium chromate, 

 and a nontiltered 0.1 per cent hydro alcoholic solution of eosin. These are 



