AGRICULTURAL CHEMISTRY — AGROTECHNY. 207 



orated in a platinum dish and treated in the usual manner. According to the 

 author, it requires about 4 hours to destroy completely 300 gm. of organic 

 matter (organs). 



Experiments on the water content of lard from. Danish packing houses, 

 N. O. Hofman-Bang and E. Holm {Ber. K. Vet. og Landholmjslcoles Lab. 

 Landokonom. Forsog [Copenhagen], 13 (1911), pp. 28). — The results of the 

 investigation indicate that lard containing less than 0.3 per cent moisture (the 

 maximum water content allowed in lard destined for export to Germany) can 

 be obtained by adding from 2 to 3 per cent of water to the refining kettle 

 and then heating the fat until it is entirely clear ; at this point the temperature 

 will rise to 110° C. If the lard remains clear when cooled to 65° it is stated 

 that it will contain less than 0.3 per cent water. 



The report also gives an account of investigations in regard to the fat con- 

 tent of fat residue cakes and of extracting grease for making soap. 



Determination of sucrose in cane molasses; use of hydrochloric acid and 

 urea for the direct polarization, H. Pellet (Internat. Sugar Jour., 13 (1911), 

 No. 1^8, pp. 206-209). — ^A study was made of the application of Andrllk's hydro- 

 chloric acid and urea mixture and of sulphurous acid to the analysis of cane 

 products, particularly cane molasses. 



The reaction of the 2 reagents was found to be somewhat dissimilar. The 

 reason was supposed to lie in the fact that in low-grade cane products the 

 sugars and nonsugars are not uniform. In low-grade products the reducing 

 substances vary from 10 to 30 per cent. 



As the levorotation of an invert sugar increases with the concentration of 

 hydrochloric acid in the solution, the value eventually found for sucrose is too 

 high when this acid is used for inverting the sucrose present in the same solu- 

 tion. " If, however, before inversion the liquid is polarized with the addition of 

 10 cc. of the hydrochloric acid and urea mixture, and this direct polarization 

 taken with the inversion polarization (for which only hydrochloric acid, and no 

 urea is used), the actual amount of sucrose present is obtained, since the 

 change of rotation is due only in this case to hydrolyzed sucrose. . . . 



"The application of sulphurous acid to cane molasses [was studied], but 

 in this case this acid [did] not give the same results as in the analysis of beet 

 products, since it has not the same action upon the levorotation of reducing 

 sugar as hydrochloric acid. Hence the hydrochloric acid and urea is indis- 

 pensable for effecting the exact estimation of sucrose in cane molasses." 



Analysis of honey, with special reference to the nitrogenous constituents, 

 R. Lund (Mitt. Lebensni. Untersuch. u. Hyg., Schiceiz. Osndhtsamt., 1 (1910), 

 No. 1, pp. 38-58; ahs. in Chem. ZentU., 1911, I, No. 15, pp. 1158, 1159; Analyst, 

 36 (1911), No. 423, p. 277).— About one-half of the total nitrogen in genuine 

 honey, according to this author, consists of protein nitrogen and the other 

 half of amino nitrogen. The total nitrogen present in genuine honeys was 

 from 0.31 to 0.45 per cent, while artificial honeys contain only from 0.106 to 0.2 

 per cent. The amount of ammonia present is very small, and can be ignored. 



For estimating the protein nitrogen in honey the author uses the following 

 method: A solution consisting of 2 gm. of phosphotungstic acid in 20 gm. of 

 dilute sulphuric acid (1:4) and 80 cc. of water is used as the precipitating 

 reagent. " Five cc. of this reagent is added to 20 cc. of a filtered 10 per cent 

 solution of honey, the mixture being diluted to 40 cc. and stirred. The pre- 

 cipitate separates better in this way than when tannic acid is used, and the 

 results are equivalent. Precipitation is effected in the test tubes employed by 

 Barth for the estimation of tannin in wine. The volume of the precipitate is 

 read off after 24 hours, and in the case of natural honey it ranges from 0.6 

 24971°— No. 3—12 2 



