AGEICULTUKAL CHEMISTRY AGEOTECHNY. 309 



instance did a decided diminution of the acidity talie place. Such diminution 

 as did occur is due in part to a precipitation of the tartaric acid and partly to 

 the action of the succinic acid decomposing bacteria. The influence of the 

 climatic condition on the above results is also considered. 



Estimation of free and combined sulphurous acid in wines, P. Cazenave 

 (Ann. Falsif., 3 {1910), No. 18, pp. 154-158, fig. 1; abs. in Jour. Chem. Soc. 

 [London], 98 (1910), No. 512, II, p. 5/,-i).— The author observed by actual test 

 that the iodometric estimation of sulphurous acid is untrustworthy, and recom- 

 mends determining it by oxidation and gravimetric analysis. 



It was concluded that the total sulphurous acid is best estimated from the 

 quantity of sulphate present before and after oxidation with iodiu. The free 

 sulphurous acid can be removed by distilling the wine for 5 minutes under 

 reduced pressure at 50° C. The fixed or residual sulphurous acid is determined 

 after the distillation, and the free sulphurous acid estimated by difference. It 

 was found that it was not necessary to distill the free sulphurous acid in an 

 atmosphere of carbon dioxid. 



. Some rare oil fruits, C. Grimme {Chem. Rev. Fett u. Uars Indus., 17 {1910), 

 Nos. 7, pp. 156-158; 8, pp. 178-183; abs. in Jour. Soc. Chem. Indus., 29 {1910), 

 No. 16, pp. 1019, 1020; Chem. Zenlbl., 1910, II, No. 8, pp. 5.80-582).— Chemical 

 and physical data are reported in regard to the fat, oil, etc., obtained from the 

 following fruits: Acrocomia fotai, Ximenia americana, Moqulliu tomentosa, 

 Pentaclethra macrophylla, oil fruit from Guatemala, Canarium olcosum, Carapa 

 procera, oil fruit fi'om Mexico, Sterculia appendiculata, Mesua ferrea, Termir 

 nalia catappa, Acanthosicyus horrida, and Citrullus naudinianus. 



Detection of lemon oil in orange oil, E. M. Chace and A. R. Albright {Abs. 

 in Science, n. ser., 32 {1910), No. 823, p. 475). — The authors rely on the refrac- 

 tive indexes of the aldehydes contained in lemon and orange oil as a basis. 

 These aldehydes are separated by the formation of double sulphite compounds, 

 which are eventually decomposed with sodium carbonate and caustic soda uuder 

 ether. The ether is then evaporated and the refractive index is taken of the 

 residue after drying and purification. Citral has practically the same index 

 as the aldehydes from pure lemon oil. The method is only approximately 

 quantitative. 



Quantitative determination of benzoic acid in foods, F. H. Van Der Laan 

 and H. Tijdens {Chem. Weelcbl, 7 {1910), No. 27, pp. 603-615; abs. in Chem. 

 Zentbl., 1910, II, No. 7, p. .!,96). —li is stated that this is best done by adding 

 alkali to the sample, extracting with warm water, acidifying, and extracting 

 with Van Ledden Hulsebosch's perforation apparatus for 5 hours with an acid 

 solution of benzol. After the extraction process the benzol is washed with a 

 little water to remove the foreign acids which may be present and then titrated 

 with a decinormal sodium hydrate solution and phenolphthalein. If salicylic 

 acid is simultaneously present with the benzoic acid the salicylic acid may 

 be destroyed by oxidizing with potassium permanganate in a weak alkaline 

 solution. 



The analysis of Emmental cheese, G. Koestler {Milchic. Zentbl., 6 {1910), 

 No. 7, pp. 289-299). — In determining the dry substance in Emmental fat cheese 

 no difficulty was experienced in obtaining good constant weights when from 

 5 to 8 gm. of finely ground cheese were weighed out quickly (with the weighing 

 bottle and by difference) into flat porcelain dishes, placed in a vacuum desic- 

 cator for a day, and finally dried in a hot-water oven from 2 to 2* hours 

 until comparative estimations yield no more than a difference of 2 mg. 



The fat in Emmental cheese which is manufactured uniformly is very evenly 

 distributed throughout the cheese mass. When sampling cheeses which are 

 not overripened the results show that it is best to take the sample in the 



