SCIENTIFIC NOTES ON ESSENTIAL OILS. - 11 
of lead acetate are added. The precipitate is collected on a tared Gooch filter (packed 
with ignited asbestos), thoroughly washed with 70 p.c. alcohol, and dried at 100° 
until constant weight is attained. The filtrate should be tested with more of the lead 
acetate solution and any further precipitate filtered off. 
In this way an oil mixed with 10 p.c. of rosin gave 10,6 p.c. precipitate; one 
containing 15 p.c. gave 15,2 p.c., and one with 20 p.c. showed 19,7 p.c. of precipitate. | 
Two pure cassia oils, containing 92 and 88p.c. of aldehyde respectively, and acid 
values of 6 and 13, yielded no precipitate with lead acetate. Three other oils gave 
10,1, 10,6 and 10,1 p.c., respectively. In these latter oils the aldehyde» percentages 
were 82, 72, and 73 p.c., respectively, acid v. being 27, 23 and 29. These latter figures 
cannot be relied upon in the quantitative determination of added rosin, because the 
oils themselves contain varying quantities of cinnamic acid; the acid values do not, 
therefore, permit of any direct conclusions concerning the quantities of rosin present 
in the oil*). . : 
The author of above article believes that his observations justify the conclusion 
that about 10 p.c. of rosin are systematically added to cassia oil in certain parts of 
‘the country of origin. 
Oil of Cathetus fasciculata. On page 102 of our Report April 1914 we had 
given a description — under “Novelties” — of the oil of Cathetus fasciculata, Lour. 
(Euphorbiaceae). At the very same time a description also appeared in the Report of 
Roure-Bertrand Fils’). According to Roure-Bertrand Fils the mother-plant is a shrub 
about 3 feet high, with twigs pointing upward, with entire, flat and glabrous leaves; 
the flowers are small, axillary or singly arranged. According to Murat the shrub is 
in full florescence in the month of August. Distillation begins towards the end of 
January and yields varying results, according to soil and according to whether fresh 
or dried plants are used. Consequently the oil is sometimes of a green, sometimes of a 
yellow colour. Differences in soil may possibly account for these differences in 
colour. The properties of green as well as of yellow oils observed by Roure-Bertrand 
Fils, as well as our own observations, are collected in the table below. The oil con- 
tained 31 p.c. of cineol (resorcinol method). 
Oil 
Wigeen ~ yellow Schimmel & Co. 
Biase ts Se 2 Fe OS8H1 0,8862 . 0,8897 
eee Bee ee tT iets et! = BO AL)’ — 1°22’ — 4° 34’ 
PEM e Hee MAN vid, A AGE 0,7 1,9 
een etl? Soo eure Va Age 3,9 3,7 
ester value after acetylation 42,0 49,5 44,8 
SOG Whose oe 4,5 volumes. -3 volumes — 
and more of 85 p.c. alcohol. 
Oil of Chamaecyparis Lawsoniana. Of the “Port Orford cedar” (Chamaecyparis 
Lawsoniana, Parl., N.O. Pinaceae) only the oil of the leaves had been prepared so far®). 
1) In the above article it is stated that C. F. Yates [Perfwm. Record 3 (1912), 83] recommended the acid 
value being made use of in the determination of colophonyin cassia oil. To obviate misunderstandings we may 
_ Say this was done first by H. Gilbert [Chem. Ztg. 13 (1889), 1406] who laid special stress on the usefulness of 
the acid value in the quantitative determination of the rosin. In the course of the years we have repeatedly 
pointed out how acid value in cassia oil is increased by colophony. — *%) Berichte von Roure-Bertrand Fils 
April 1914, 5. — #) Report October 1910, 144, 145. 
