OLIVE OIL AND ITS SUBSTITUTES. 



are not of much value for comparative purposes, but if there is only a 

 slight difference in strength they give very satisfactory results. The 

 variation is least when a strong acid is used, giving a rise of tempera- 

 ture with water of 48.9 C. to 47.5 C., showing that the Maumene 

 number obtained on olive oils with strong acid is more uniform than 

 with the weaker acid. However, the strong acid is not satisfactory 

 for use on seed oils, as the reaction becomes too violent and the oil is 

 broken up. With seed oils a weaker acid was used, as suggested by 

 Sherman, Danziger, and Kohnstamm." 



The following table gives the results obtained in this laboratory on 

 various oils. The strongest acid was used on the olive and lard oils, and 

 a weaker acid on the seed oils. 



TAHLK X. Man incur and */>i'<-ijir temperature numherx of rnrlous o //.<?. 



aAcids of quite widely differing strengths were used in these determinations. 



IODIN ABSORPTION. 



The method used for this determination was the modified Hiibl 

 method, a^ adopted b}^ the Association of Official Agricultural Chem- 

 ists/' in which the iodin solution is alloAved to stand in contact with 

 the oil for three hours. 



The iodin number was found to be exceedingly variable. On 42 

 samples of California oil examined the range was 7s.f> to s..x. \\jtli 

 an average of 85.1. Hlasdale'' found a range of from so to s'..\ with 

 an average of S4. Colby' 7 gives a range, of 77.7 to JW.f> for California 

 oils of known purity. On 17 samples of Italian oils the variation was 

 from 7l.i > to 86.1, with an average of si.r>. De Nogri and Fabris' 

 found on 88 samples of pure Italian oils a range of from 7i>. 1 to SH.s. 

 with an average of SI',. 7. Milliau' found for French oils a range of 

 from M to s:>. and for the oils of southern Kuro]>e and Tunis a range 

 of from si. 4 to S.VJ. Later '' he found on Tunis oils a range of 7'.'.: 1 . 

 to 99.5, with an average of sr>, figures which are very similar to the 



"Jour. 4mer.Chetd.8oc., I'.<>L'. iM: 266. 



''I', s. i >,.,,t. A-r., Divinon of Chemistry liul. 4i, |.. :>o ; liui. ;:>. p. LM. 



-.lour. AHMT. C'licin. Sec., is'.i:,, 17: 935, 



-'California A-r. K\pt. Sta. K.-pt., L897 98, p. 16S. 



' Annali <h-l Labor. <-him. ccntr. d.-ll.- Cah.-ll.-, v..l. I, <ili olii. pt. 1, p. 38. 



/Bui. ilu Ministrn-.il- V \irriiMiltun-. is ( .:>. p. l.'.'.i. 



J/ Milliau, Bertainchand, and Ma'u-t. Kaj.port surlrs huilrs .Tolivr <1<- Tunisio, 190a 



