1917] AGEICULTUEAL CHEMISTRY AGROTECHNY. 313 



procedure is indicated as being easy to manipulate and to be applicable to a 

 variety of substances. 



Some analytical data submitted indicate the accuracy of the procedure. 



Detection of lime used as a neutralizer in dairy products, H. J. Wichjiann 

 {U. S. Dept. Agr. Bui. 524 (1917), pp. 22).— From an analytical study of the 

 calcium osid in cream, the total ash and the salt-free (sodium-chlorid-free) 

 ash, 25 per cent calcium oxid in the salt-free ash was found to be a good maxi- 

 mum standard. If the calcium oxid percentage is below 25 it is considered that 

 the butter may be classed as made from unlimed cream, while samples with 

 calcium oxid percentages between 25 and 28 in a salt-free ash should be con- 

 sidered suspicious. In cases of doubt as to the possibilities of the presence of 

 large amounts of calcium sulphate in the salt used, a sulphate determination 

 should be made and the proper correction applied. The effect of calcium 

 chlorid, magnesium chlorid, and sodium sulphate which might be present in the 

 salt used was studied, and the amounts ordinarily present found to have no 

 effect. 



The use of lime in renovating old storage butter is noted and briefly discussed. 



Analytical data of the ash of a number of creams before liming, of butter 

 made from unneutralized cream, of salted and unsalted butters made from 

 unneutralized cream, and of unlimed and limed dairy products are submitted. 



The determination of sugar in g'ummy substances, G. Sa\ini (Ann. Chim. 

 Appl. [Rome^, 6 (1916), No. 9-12, pp. 250-255). — In the examination of gummy 

 substances the results obtained by Fehling's solution were higher than those 

 obtained by the optical procedure (Clerget's formula). During the inversion in 

 the presence of gum appreciable amounts of dextrorotatory material were 

 found to be formed, which caused the discordant results. This was obviated 

 by defecating the sample with basic lead acetate and 95 per cent alcohol. An 

 aliquot from the defecated material is evaporated to remove the alcohol, the 

 residue dissolved in water, and the excess lead removed with alum. The 

 clear filtrate is then treated in the usual manner. 



Some analytical data are submitted. 



The quantitative determination of minute amounts of sugar by a-naphthol 

 and the estimation of entrainment losses, A. F. Blake (Internat. Sugar. Jotir., 



19 (1911), No. 217, pp. 26-28, fig. i).— The following procedure is described : 

 Five cc. of the solution to be tested is placed in a perfectly clean vial and five 



drops of a 20 per cent solution of a-naphthol in pure alcohol, together with 

 10 cc. of concentrated sulphuric acid, are carefully added. The mixture, which 

 becomes very hot, is immediately stirred with a glass rod. In the presence of 

 sugar a purple-red color develops, the intensity being proportionate to the 

 amount of sugar present. After two minutes the color of the solution in the 

 vial is compared with that of a standard prepared in the same manner as the 

 unknown sample. 



It is indicated that the error in developing and matching the colors is about 



20 per cent. The reaction is not specific, but it is noted that the impurities 

 which might be present do not introduce a great error. The presence of iron 

 interferes somewhat by producing a peculiar coloration. 



The test is of special value in determining entrainment losses. 



The utilization of cull citrus fruits in Florida, F. A. McDebmott, sum- 

 marized by S. S. Walker (Florida Sta. Bui. 135 (1917), pp. i 29-/^-}). —The 

 results of the investigation show that both orange and grapefruit juice can 

 be preserved in the original condition at least for 18 months and probably 

 Indefinitely by pasteurization in the absence of air. Aiter proper clarification, 

 the juice may be concentrated by vacuum evaporation to about 20 per cent of 

 its original volume. The concentrated product, flavored with orange extract, 



