AGRICULTURAL CHEMISTRY AGROTECHNY. 513 



ing and preventing as much as possible the formation of an emulsion, the 

 mixture is allowed to stand for a time. If fuchsin is present, the paraldehyde 

 layer will be red in color. The reaction is sensitive to 1 part in a million. 



(b) One cc. of the sample is diluted with 2 cc. of water. Then 2 cc. of a 

 saturated solution of salicylic acid in chloroform is added, shaken, and allowed 

 to stand. The presence of fuchsin is indicated by the red coloration of the 

 chloroform layer. 



Olive oil, E. R. Miller (Proc. Ann. Conv. Ala. Pharm. Assoc, 21 (1908), 

 pp. 71-73). — The results of analyses of 30 samples of olive oil collected in 3 

 different States showed a positive Halphen reaction in 11 instances. The nitric 

 acid test and silver nitrate test, on the other hand, showed a slight reaction in 

 some instances where none was apparent with Halphen's reagent. 



Pecan oil, A. C. Deilee and G. S. Fraps {Amer. Cliem. Jour., i,3 (1909). No. 1, 

 pp. 90-91). — An anaylsis at the Texas Experiment Station of pecan oil obtained 

 from pecan nuts which consisted of 47 per cent kernels and contained 70.4 

 per cent of oil, gave the following results: Specific gravity 15° C. 0.9184, 

 saponification value 19S.0, iodin absorption (Hiibl's method) lOG.O, volatile 

 acids (Reichert-Meissl value) 2.2, acetyl value 1.16. insoluble fatty acids 

 (Hehner value) KM. 4 per cent, lecithin 0..~) i)er cent, and cholesterol 0.2S per cent. 



A method for the determination of citral in lemon extracts and lemon oils, 

 R. S. HiLTNER (Jour. Indus, and Engin. Chem., 1 (1909), No. 12, pp. 798-800).— 

 The method is a colorimetric one, using Schreiner's apparatus and a 1 per cent 

 solution of metaphenylenediamin hydrochlorid in 50 per cent ethyl alcohol as 

 the reagent. All operations may be carried on at room temperature. 



The determination of essential oil and moisture in spices and aromatic 

 drugs, R. A. Cripps and J. A. Brown (Analyst, S.'f (1909), No. J/Oo, pp. 519- 

 523). — The authors did not obtain good results by determining the oil and 

 moisture directly and therefore suggest employing an indirect method, that is, 

 determining (a) moisture and (b) total volatile matter, the difference being 

 the essential oil. 



The moisture is determined by heating the spice in a stout tube according 

 to Dupre's method for cordite, allowing the vapor therefrom to act upon calcium 

 cai-bid and measuring the amount of acetylene formed in a nitrometer. The 

 number of cubic centimeters of gas obtained multiplied by 0.001725 giving the 

 weight of water in the sample. For the total volatile matter (essential oil 

 plus moisture), the authors heat a tube containing the spice at a temperature 

 of 135° C, passing a current of air through it simultaneously for a period of 

 1 hour or less, and noting the loss of weight. 



Detection of coffee adulterations, M. Cantagrel (Ann. Falsif., 2 (1909), 

 No. 12, pp. Jt60-'i63; abs. in Chem. Ztg., 33 (1909), No. 136, Repcrt., p. 582).— 

 The method is based on the fact that coffee contains about 25 per cent of total 

 extractive matter, so that for every 5 gm. of coffee substitute present there is a 

 diminution of this extract by 1.2 per cent. It is further shown that coffee has 

 a maximum reducing value, so that any values beyond this indicate adultera- 

 tion with some roasted substance containing sugar. 



On the phosphates in certain vineg'ars and in the materials used in their 

 manufacture, T. Fairley (Analyst, 3.'t (1909), No. J,05, pp. 515, 516).— The 

 author investigated certain vinegars which, though normal in other respects, 

 did not have the requisite amount of phosphates present. It was found that 

 the mash of these vinegars was made partly from corn and was filtered pre- 

 vious to fermentation, so that a considerable amount of the phosphates was 

 retained in the draff or grains. 



Iron as an ag'ent causing discoloration of food products, E. W. Duckwall 

 (Canncr and Dried Fruit Packer, 29 (1909), No. 23, pp. 27-30). —Largely on 



