314 ODOROGRAPHIA. 



According to " Pharmacographia," the dried root yields IS per 

 cent, of a neutral, yellowish esential oil of agreeable odour, 

 deviating the polarised ray 13*^ 8' to the right in a 50 m. m. tube. 



Osse estimated the percentage of volatile oil in the dried root at 

 the high figure of 3-90.* His method of determining the amount 

 of volatile oils in plants is as follows : — Five grams of the finely 

 powdered substance are shaken with 25 c. c. of petroleum ether 

 (boiling-point not exceeding 40° C.) for several hours ; the 

 undissolved matter is then allowed to subside ; 1 c. c. of the clear 

 liquid is drawn off", evaporated on a watch-glass in a current of dry 

 air until the odour of the ether is no longer perceptible. The glass 

 with contents is then weighed, the volatile oil driven off by heat 

 and again weighed, the difference of the two weighings indicating 

 the quantity of volatile oil. When the volatile oil is associated 

 with a large quantity of fixed oil, a correction must be made for a 

 very slight increase in weight, resulting from the heating of the 

 fixed oil in air. For non-drying oils, O'OO per cent, of the weight 

 of the fixed oil is added to the weight of the volatile oil found." 

 The amount of fixed oil, or resin found by Osse, working by this 

 method, w^as 0'75 per cent. 



Messrs. Schimmel have obtained by distillation of the chied 

 German root 1-5 to 3-5 per cent, of volatile oil ; sp. gr. 0*960 to 

 0-980 at IS'^ C. ; optical rotation -1- 15° to + 21° in 100 m. m 

 tube. From the fresh German root they obtained 0*8 per cent. ; 

 sp. gr. 0-960 to 0-970; optical rotation -f 21° to + 31°.t The 

 same observers report on a parcel of calamus root received from 

 Japan, that these roots do not differ externally from European 

 calamus roots and are no doubt derived from the same 

 species ; they contain Jive per cent, of a highly aromatic essential 

 oil having a sp. gr. of 0-985 to 1-00 at 15° C, which is con- 

 siderably heavier than the German calamus oil. This oil boils 

 between 210° and 290° C. ; if the distillate be collected in 

 two fractions, the lower portion has the characteristic calamus 

 odour, while the higher boiling portion gives off the peculiar 

 sesquiterpene odour. Japanese calamus oil also differs from the 

 European in solubility, one part dissolving in 500 parts of 50 per 

 cent, spirit, the German oil requiring 1,000 parts of the same.:|: 



* Zeitschr. Oest. Ap. Ver., 1875, p. 441. 

 t Bericht, October, 1893. 

 ::: Ibid, April, 1889. 



