RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY. 



A single standardizing material for acidimetry and alkalimitry, E. Rupp 

 (Chem. Ztff., SI {1901), No. !), p. .07).— The author tested with success and 

 recommends for this purpose wealv solutions (preferably tenth-normal) of care- 

 fully purified borax to which glycerin or mannite is added. 



On the rapid determination of carbon dioxid in confined and free atmos- 

 pheres, A. MiJNTz, E. Laine, and R. Gallois (Ann. Inst. Nat. Agron., 2. ser., 

 ■) {11)1)6), No. 1, pp. 1.3-30, fiffs. .'/). — A titrimetric method is described in which 

 the carbon dioxid evolved is absorbed in dilute alkali, the excess of alkali be- 

 iiiLC titrated with a solution of sodium l)icarbouate. using I'oirrier's blue as an 

 Indicator. By means of a si)ecial apparatus, which is fully desci'ibed, the 

 carbon dioxid as it is evolved is made to pass through the alkali solution very 

 slowly and in a very flue state of division, thus insuring perfect absorption, 

 'rhe fine division of the gas bubbles is secured by means of a si)ecial device 

 \\hicli forces the gas to pass through a soap solution. 



The method was successfully applied to confined air and to the free atmos- 

 phere in the garden of the National Agronomic Institute at Paris. In a series 

 (if observations in the latter case the amount of carbon dioxid in the atmos- 

 phere varied from L'.S" to r5.L'4 parts i)er 1.000. 



On a new method for the determination of ammonia in waters, A. Buissox 

 ( Vonipt. Rend. Acad. Sci. [Paris], lU (1907), No. 9. pp. J,93-.'i9.j ; uhs. in Rev. Hri. 

 \Pari.'<], 5. ser., 7 (1907), No. 11, p. 33.S).— The method is based upon the fact 

 that if mercuric chlorid is added to a solution of an ammonium salt containing 

 sodium carbonate in the proportion of .^ molecules of mercuric chlorid to 2 mole- 

 cules of the ammoniacal salts anunonia is completely precipitated in the form 

 of a white amorphous compound having the formula C03(Hg5NoCl,),0+3H20. 



The method is carried out as follows : Add 5 cc. of a 1:4 soda solution to 1 

 liter of water and distill about 100 cc. into 10 cc. of 1 per cent hydrochloric 

 ;icid, make the volume to 1 liter, add 10 cc. of a ."> per cent solution of mercuric 

 chlorid and 10 cc. of a 15 per cent solution of sodium cai-bonate. let stand for 

 24 liours, collect on a tared filter, wash with r> cc. of water, dry at 100° C, and 

 weigh. The weight thus obtained nniltiplied by 0.03 gives the ammonia in 1 

 liter of water. With water containing less than 1 mg. of ammonia per liter, 

 precipitate in the 100 cc. distillate without dilution. 



The results by this method are claimed to be as good as those by ordinary 

 methods. 



The determination of manganese in drinking water, II. Lliirig and W. 

 Becker (Pharm. CentralhaUe, .'i8 (1907). No. 8, pp. 137-11,2).— The Knorre 

 method, based upon the precipitation of the manganese by ammonium persul- 

 phate in boiling solution, dissolving the precipitate, and titrating the solution 

 thus obt.-iincd. is roconimended. 



A delicate reaction for carbohydrates, II. .J. II. Fkntox (Proc. Cambridge 

 Phil. Hoc., IJ, (1907)', No. 1, pp. 2//-26).— It has been observed that when bromo 



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