610 EXPERIMENT STATION EECOBD. 



R., 20, p. 113)'. The method is based upon the preliminary oxidation of the 

 substance with fuming nitric acid and the further oxidation with copper nitrate 

 and potassium chlorate." 



Volumetric method for free sulphuric acid and sulphates, F. Repiton 

 {AlonU. Sci., 4. ser., 24 {1910), I, No. 822, pp. 382-384; ahs. in Ztschr. Angeio. 

 Chem., 23 (1910), No. 40, p. 1912). — The sulphuric acid is precipitated with a 

 barium chlorid solution of known strength, and the excess of the latter removed 

 with a solution of potassium bichromate of known titer. The amount of this 

 bichromate employed is determined with stannous chlorid and with the aid of 

 mercuric chlorid as the indicator. 



The use of phenol for determining calcium, and magnesium, L. Lindet 

 and Brasaet {Ann. CMm. Anwlyt., 15 {1910), No. 8, pp. 293-295).— Essentially 

 this method has been already noted from another source (E. S. R., 23, p. 705). 



A practical manual for the analysis of soils, F. Hiti {Estac. Agr. Cent. 

 [Mexico] Bol. 26, pp. 56, pis. 3). — :Methods for the approximate and complete 

 analysis of soils are summarized. 



The determination of formic acid in the presence of acetic acid, M. H. 

 Delehaye {Ann. FaJsif., 3 (1910), No. 23, pp. 386-388). — The method is based 

 on the reduction of mercuric sulphate to insoluble mercurous sulphate. 



Preservatives in fruit juices, with particular reference to detecting' formic 

 acid, LoocK {Ztschr. Offentl. Chcm., 16 {1910), No. 18, pp. 350-354 ) .—After 

 reviewing the various preservatives utilized for conserving fruit juices, the 

 author points out that formic acid is a normal constituent of fruits but that 

 the amount contained therein is very limited. The various qualitative and 

 quantitative methods for estimating this acid are then considered, and from 

 his results it is concluded that not much reliance can be placed on the quali- 

 tative detection of formic acid on the basis of its reducing action in the 

 aqueous distillate. A more exact method is, particularly for small amounts, 

 by allowing sulphuric acid to act on the distillate residues which have been 

 previously treated with lead oxid. This liberates carbon mouoxid which is 

 passed through defibrinated blood and the carbon monoxid hemoglobin spectrum 

 noted therein. 



Examination of honey, with particular reference to the Ley, Fiehe, and 

 Jagerschmid reactions, F. Reinhaedt {Ztschr. Untersuch. Nahr. u. GenussmtL, 

 20 {1910), No. 3, pp. 113-152). — The avithor concludes from the results of his 

 examination of various honeys that Ley's reaction is conclusive only when 

 Fiehe's and Jagerschmid's reactions yield positive results. Fiehe's reaction 

 is positive only when it yields the characteristic dark cherry-red coloration 

 with both a 38 and 25 per cent hydrochloric acid-resorcin solution. Jager- 

 schmid's reaction is positive when either a red or violet or a carmine-red color 

 is produced, and always when Fiehe's reaction is obtained. 



According to the author, a honey analysis should include the estimation of 

 the water content, polarization of a 10 per cent solution before and after in- 

 version, Fiehe's reaction, Jagerschmid's reaction, and tannin plecipitation ac- 

 cording to Lund. If Fiehe's and Jagerschmid's reactions are both positive it is 

 then ad^'isable to try Ley's reaction and make a determination of the ash. 



The results of numerous analyses of honey are appended. 



Tests in regard to the methods for estimating starch in table mustard, 

 H. Kreis {Chcm. Ztg., 34 {1910), No. 115, pp. 1021-1023; ahs. in Schweiz. 

 Wchnschr. Chem. a. Pharm., 48 {1910), No. 52, pp. 793-795).— The methods 

 considered for this work were (a) hydrolyzing in the autoclave, saccharifying. 



o Jour. Biol. Chem., 6 (1909), pp. 363^71. 



