RECENT WORK IX AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY. 



The permanent committee on the analysis and control of agricultural 

 products, L. Grandeau [■lour. Agr. Prat., n. ser., 11 {1906), No. '/. pp. 101, 

 1<>2). — The duties of this committee, consisting of 32 memhers (including some 

 of the most eminent scientific men of France), appointed by the minister of agri- 

 culture December 15, 1905, under the provision of a law of France of August 1. 

 1905, for the repression of fraud in foods, feeding stuffs, seeds, fertilizers, and 

 agricultural products in general, are explained." The committee has organized 

 into a number of subcommittees for the -consideration of different phases of 

 its work. 



Methods of analysis of fertilizers in different countries, L. Sicard {Ann. 

 Ecolc Nat. Agr. Montpellier, n. scr.. 5 {1906), No. 3. pp. 20^-222). — This is the 

 third report on this subject, and deals with methods of determining potash, 

 describing the various methods which have been proposed for this purpose. 

 The decisions of the Fifth International Congress of Applied Chemistry with 

 relation to the analysis of nitrates are also given. 



On the importance of uniform international methods of analysis, II. Xrs- 

 sensox (Chan. Ztf/., 30 {1906). No. 3. pp. Id, 17). — A number of illustrations 

 of the need of such methods are cited. 



New method for the determination of atmospheric carbon dioxid, based 

 on the rate of its absorption by a free surface of a solution of an alkali 

 hydroxid, II. T. Bbown and F. Escqmbe {Proc. Roy, Soc. [London]. Scr. B, 

 76 (190.1), No. B507, pp. 112-117: aos. in -lour. Chem. Soc. [London]. 88 

 i ino:,). No. 518, II. p. 80S). — The method proposed is based upon the fact that 

 when a current of air containing a constant proportion of carbon dioxid is 

 drawn over the free surface of a solution of sodium hydroxid the rate of 

 absorption increases with the velocity of the current up to a certain point, 

 beyond which it remains constant. Furthermore, the rate of absorption is pro- 

 portional to the partial pressure of the carbon dioxid within fairly wide limits. 



In the method described the air is aspirated through the apparatus at a rate 

 greater than that required for maximum absorption, and being drawn through 

 a perforated plate is made to impinge in a turbulent stream on the surface of 

 a standardized solution of sodium hydroxid. which is titrated after the experi- 

 ment. A constant for the apparatus having been determined in a preliminary 

 experiment, in which the air is measured, the proportion of carbon dioxid in a 



« For composition and duties of this commission and the law under which it 

 was appointed, see also Jour. Agr. Prat, 11. ser., 10 (1905), Nos. 32, p. 1S1 : 52, 



p. ser,. 



830 



