446 RECORD OF SCIENCE FOR 1887 AND 1888. 



The fatty acids of the dryinp oils. — ]Srorton and Eicbardwon, in an 

 investigation of linoleic acid prepared from linseed oil, have come to the 

 conclusion that it is a mixture. About three-fourths of the original 

 sample proved to he volatile, distilling under reduced pressure at 390° 

 C. Riciuoleic acid exhibits a similar volatility, the nou-volatile resi- 

 due amounting to about oue-fourth of the sample, and solidifying upon 

 cooling. The volatile parts of the two acids appear to be identical, and 

 to agree with the formula C2oH;i602. Further investigation is prom- 

 ised. (Am. Chem. Jouru., X, 59 ) 



Tests/or fats and oils. — This subject has been elaborately studied by 

 Prof. H. W. Wiley, in the laboratory of the United States Department 

 of Agriculture. On account of the increase in the use of cotton-seed oil 

 as an adulterant of other oils, and in the manufacture of imitation lard 

 and "butter, he has paid special attention to its detection, and finds that 

 Bechi's test for it is the most trustworthy. That test is based upon the 

 fact that of all the fatty oils, cotton seed oil alone is able to reduce salts of 

 silver. First, a solution of silver nitrate in water is prepared, to which 

 a large proportion of alcohol and ether is added. Secondly, a mixture 

 of amyl alcohol and rapeseed oil is provided. On adding to a suspected 

 oil, first the silver solution and then the amyl alcohol preparation, and 

 heating upon the water bath, the cotton-seed oil is readily detected. If 

 it is present a color varying from brownish to black is developed, incon- 

 sequence of the deposition of metallic silver. 



With the aid of Abbe's refractometer, he has also studied the refrac- 

 tive indices of many fats and oils, finding such wide differences between 

 them as to justify the use of the instrument in the discovery of adultera- 

 tions or the identification of samples. (Journ. Anal. Chem., ii, 275 and 

 277.) 



The composition of Jaiianese birdlime. — This substance, which is pre- 

 pared like European bird-lime from a species of holly, is extensively 

 used in Japan for catching birds and insects. According to Divers and 

 Kawakita it contains, apart from mechanical impurities, such as bark 

 and dirt, some lime salts, caoutchouc, and a number of interesting 

 organic compounds. Upon saponification with alcoholic potash it yields 

 the potassium salts of palmitic acid and of a semi-solid acid not farther 

 identified, a resinoid substance, and two crystalline alcohols. The latter 

 are named mochylic and ilicylic alcohols and melt at 234° anrl 172°, re- 

 spectively. Mochylic alcohol is represented by the formula C26H46O, 

 while ilicylic alcohol is €22^330. The ilicic alcohol, obtained by Per- 

 sonne from European birdlime is C25H44O, and, being made from a dif- 

 ferent species of holly, is probably a distinct compound. The three 

 alcohols are homologous, and belong in a series having the general 

 formula CnH2a_60. The resinoid constituent of Japanese bird-lime has 

 the composition C26H4iO, differing from mochylic alcohol by having two 

 atoms less of hydrogen. (Journ. Chem. Soc, Liii, 2G8.) 



A solid hydrocarbon in plants. — Helen C. de S.«ibbott and H. Trimble, 



