Jan.,
1920
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N EE R I N G C H E M I S TR Y
.........
0.8997 Specific gravity (15' C . ) . . . . . . . . . . . . . . . . . . . 91.3 Acid value.. ..................... Saponification value. . . . . . . . . . . . . . . . . . . . . . 107.0 177.6 Iodine value (Wijs). 1.4769 Refractive index (20' C . ) . . . . . . . . . . . . . . . . . . . 33.00 per cent Unsaponifiable matter.
OCCURRENCE OF SQUALENE IN THE EGG OIL FROM SHARK By Mitsumaru Tsujimoto IMPERIAL INDUSTRIAL LABORATORY, YETCHIU-SHIMA, TOKYO, JAPAN Received May 14, 1919
A female specimen of t h e shark named Kinbei-zam6, Lepidorhinus k i n b e i (Tanaka), which was used for t h e examination of liver oil, contained twelve eggs. The eggs were soft and had a light orange-yellow color. They were of large ellipsoidal forms, with longer diameters of about 7 cm., and weighed on an average of 140 g. Nine eggs which had a total weight of 1 2 6 0 g. were crushed t o a paste and heated with an excess of alcoholic potash, then t h e soap decomposed with hydrochloric acid and the f a t t y matter taken u p with ether. On evaporating off t h e ether from t h e extract, 218 g., 17.3 per cent of t h e f a t t y matter, were obtained. It was a light brown-colored substance and mainly solidified at the ordinary temperatures. The numerical properties of t h e substance were as follows :
73
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On passing dry HC1 into t h e well-cooled ethereal solution of this substance, about 2 0 per cent of a white crystalline precipitate was obtained. On recrystallizing i t from acetone it sintered a t about 110' C. and melted t o a clear liquid a t 123'-124O C. 0.2470 substance gave 0.3374 AgCl (Carius method) C1 = 33.77 per cent CsoHso.6HCl requires 33.82 per cent C1
The substance has therefore been confirmed t o be squalene hexahydrochloride. As t h e eggs were separated very carefully from t h e body of t h e shark, there is no doubt as t o t h e absence of t h e liver oil in t h e egg oil. Subsequently squalene has been directly extracted from t h e dried eggs with et%er. The egg oil from frill-shark, Chlamydoselachus anguineus (Garman), has also been found t o contain squalene.
LABORATORY AND PLANT CONSTANT TEMPERATURE STILL HEAD FOR LIGHT OIL FRACTIONATION1 By Frederick M. Washburn BUREAUOF STANDARDS, WASHINGTON, D. e. Received May 22, 1919 GENERAL CONSIDERATIONS
Because of t h e greatly increased production of cokeoven light oil, a n d t h e growing importance of the benzol industry, i t was felt t h a t a more accurate method of analysis for light oils was needed, as there is frequently a great discrepancy between t h e results of analysis of t h e same light oil, using different methods, and between t h e results obtained by different analysts, using t h e same method. This paper represents t h e results of a brief search for an improved method for t h e determination of benzene, toluene, and solvent naphtha in coke-oven or coal-tar light oil. After the light oil has been passed through t h e usual treatment for t h e determination of t h e percentage of wash oil present and t h e determination of t h e percentage of loss on washing with concentrated sulfuric acid, i t is practically a mixture of benzene, toluene, t h e three isomeric xylenes, and higher aromatic hydrocarbons, together with t h e small amounts of paraffins usually present. The xylenes and t h e higher hydrocarbons boiling between 1 3 5 O and 160' C. are classed as solvent naphtha, so t h a t t h e problem resolves itself into a separation of a mixture of benzene, toluene, and solvent naphtha. Fractional distillation furnishes t h e easiest means of accomplishing this. There are three main types of methods generally in use for t h e fractional distillation of light oil. ' I n t h e first of these, t h e light oil is distilled through a fractionating column and separated into two fractions, one a mixture of benzene and toluene, and t h e other 1
Published by permission of the Director of the Bureau of Standards.
a mixture of toluene and xylene. A portion of each of t h e two fractions obtained is subjected t o distillation in a side-neck flask, and t h e percentages of benzene and toluene and of toluene and xylene are read off from t h e curves or tables giving t h e relation between t h e composition of t h e fraction distilled and t h e temperature of distillation. The method of Hugh W. James* is an example of this type. This method is open t o objection on account of t h e serious errors introduced b y t h e estimation of t h e percentage composition from t h e boiling-point curves or tables, since small amounts of impurities materially influence t h e boiling points of t h e fractions. I n t h e second type of method, distillation is made through an efficient fractionating column, a n d t h e receiver is changed at 9 5 O C. and at 1 2 5 ' C. The fraction under 95' C. is considered as benzene, t h e fraction 95 O t o I 25 ' C. as toluene, and t h e residue as solvent naphtha. The methpd of Gustav Egloff2 is a n example of this type. This method is more logical t h a n t h e first, since it aims a t a more complete separation of t h e mixture, but i t gives fractions which are not pure. The first fraction consists of a mixture of benzene and toluene; t h e second of benzene, toluene, and xylene; and t h e residue of toluene and xylene. The results obtained depend upon t h e assumption t h a t there is t h e same amount of toluene in t h e benzene fraction as there is benzene in t h e toluene fraction, and, similarly, as much xylene in t h e toluene fraction as there is toluene in t h e residue, in which case t h e errors introduced b y assuming t h e fractions t o be pure would neutralize each other. The objection t o this method is t h a t this relation does not usually exist, since t h e amount of toluene distilling below 95' C., t h e amount of benzene 1 2
J . Soc. Chem. I n d , 35 (1916), 236. Met. & Chem. Eng., 16 (1917), 259.
