ticslly conqtmt a t 0 923 and the rcfrnctivc index varies b u t little from 1.474. The iodine number is more vnrisble, rrtngiiig from 123 2 to 132.3. Some investigators have maintained t h a t imported oils l i n i ~a higher vnlue and hencc better dryingproperties than domcsticoils, h u t these data do not bear out this contention. K'emzckl points o u t that iodine value and drying power do not ncceswrily go hand in hand, although such is often tlie case. The saponification values are fairly constnnt between 190 and 195, 9 value which is near the average for neutral oils. This higli number a190 indicntes t h n t the percentage of volatile acids is not higli and thnt thcre is but little unsaponifiable mstter. This i q of great importance to the soap manufacturer. The acid value varies considerabIy in the +cver,zl samples. Two high values were found in imported oiis. Gardner.2 in his rrpninting tests a t Washington, D. C , showed t h a t t h c acid value of n sample of soy-bean oil increawd in 2.t5yrs. from 3.5 to 5 . 7 . The drying power of the oils wss dctermincd by exposing oil films of uniform thickn w on pine hoards. Thii W L ~ inercly to cnnblc the writer to clrtss thc oil< roiiRlily ns good, fair, or poor driers. SRmplo 4 imported oil, and 'l'nrhccl nnd hIctliurn Grecri oils wcre markcdly poorer t h a n thc rest. In the former, the iodine \due is low rind thc Hcid vnlue is Iiigli. The low RcichertMcissl number shows but, II very small pcrccntngc of volatile fatty acids to l x prcscnt. The pcrccntngc of insoluble fatty acids plus the U n S ~ ~ ~ n i f i l t brnnttcr lC gives the ITclincr \.aluc of an oil. As Thompson and Morgan3 point out, this i. ndifficult dctcrmination to prrforrn with soy-bennoil, since 3 solid CRBC of thc fatty Reids is l i d to sccurr. Each result i n Table I1 rcprcxnts the nvcragc of four determinations. Since thc per cent of un5nponifinblc matter is so slight, t h e Ilehner v d u c practically rcprcscnts the insoluble fatty ncids nlnnc. Thc proportion of uns:ttumtcd to snturatcd fatty acids is ncnrly 10 to 1. I t i.; to tlie formcr t h n t soy-bean oil owes its drying propcrtics. It IY'ILSobserved t h a t some of the oils eslzmined rcmtsinctl pcrfcctly clcar,wliilc o thcrs showed :L considerable amoiuit, of foots :mi were therefore interior in qunlity It w a s also 01)scn cd thnt, in gencrnl, light colorcd bcms gnvc B pnler oil t l i n n tlic dark colored varieties, : i l ~t.hc oil appcarcd to dry inorc quickly. It is realized, howevcr, that 110 ~ o n r l u ~ i om i i ~y be (1rnn.n from this mere cibicrvation. .icc.ording to Tocll.' c.oltl-prcs~et1wy-bran oil, he2itcd to %-)OO0C. ior frorn 3 to 7 I i r G . , thickens like linsccd oil nnd attaiiis n specific gnivity of 0.!160 or more, Such nn oil is ccrtainly suit:ible for w c i n rcrtnin Iminta. In gcncral, tlic Inttcr are not ns glosy- n n d require sorncwhnt Ionger to dry tlisn 11nsccd psinL5, but ~nisturesup to 33 per ccnt or even higher have given very good rcsults in prncticnl esposure teste. It is probsbly at its bcst. when u i ~ in 1 interior paints, Imking japans, and in vnrnish. Soy-bc:in oil varnish requires longer to dry but is substantially like linsccd varnish riftcr n short cymsurc. .\nalyscs of two coinpositc snrnplcs of soy-bcwn oil, obf riiricd frorn sistccn different sninplcs of I3lnt'k ISycbrow soy Iwstns wcrc mndc, with tlic followiaji ttvcr:igc rcsults: mtumtcd ftitty acids, 9 . 2 pcr crnt; u n s a t u r a t ~ lftttty acids, 8.49 pcr cent. The values obtninecl by Thompson :ind LIorgans nn a compositc sample n g e e very ivcll with tlicsc. Educntioniil nurcnu, I'nint hIiiriutnctiircis' .\wocintioti of t h e IJriitcd 37. 3 I h i d , S O : I J t i i l r f i n 53. ' L o c CCl 4 .I So
