- 79 — 



power of the distillate. Jeancard and Satie maintain that we ourselves 

 have declared this test to be illusory on the ground that the result 

 depended entirely upon the size of the Ladenburg flask. With regard 

 to this we feel bound to state that we have never expressed such an 

 opinion of our distilling-method, and that the authors have evidently mis- 

 understood something that has been said by us. It goes without saying 

 that the test must always be carried out under identical experimental 

 conditions if it is desired to obtain comparable results, and for that reason, 

 when publishing the method 1 ), we carefully laid down the dimensions of 

 the Ladenburg flask, because of course this is a point of special im- 

 portance. In our own practice the method in question has often rendered 

 excellent service, and it is still in daily use in our laboratories, which 

 is the best possible proof that we do not regard it as illusory. It is true, 

 however, that, basing ourselves upon the experience gained by us in the 

 course of years, we have stated that a lsevorotation of the first 10°/o of 

 the distillate does not necessarily imply that the rosemary oil showing 

 such a rotation is adulterated 2 ), but it will be quite easy to judge every 

 case of this kind upon its own merits, bearing in mind the other properties 

 of the sample. 



Rue Oil. The genus Buta comprises about 50 species of which the 

 following four occur in France, namely: Buta montana, L. (B. tenuifolia, Desf.), 

 B. angustifolia, Pers. (B. chalepensis, L), B. bracteosa, D. C. and the common 

 garden rue, Buta graveolens, L. The same species, with the exception of 

 garden rue, also occur in Algeria. As reported by F. Jadin 3 ), these Buta 

 species are easily distinguishable from each other by examination of their 

 anatomic structure, sections of the stalks in particular showing charac- 

 teristic features. 



The oil of Buta montana, which is cultivated in Algeria, is usually 

 known as "essence figeable". It contains about 90% methylnonylketone 

 and solidifies completely at + 10°: di 5 o 0,8307, « D + 0°42'; soluble in 

 2 1 /i vols, and more of 70% alcohol. 



The properties of the oil of Buta bracteosa, which is also cultivated 

 in Algeria, are totally different. The oil examined by Jadin was obtained 

 from the flowering plant; it contained about 90% ^ketones, but did not 

 solidify even at — 15°: d 15 o 0,8410, « D — 4° 12', sol. in 2 vols, of 70% al- 

 cohol, when more is added the solution acquires a blue fluorescence, 

 while paraffin is separated out from it. The constants of this oil are 

 almost the same as those of an Algerian oil of rue which was examined 

 by v. Soden and Henle 4 ); hence the two products are probably identical. 



J ) Report October 1898, 41. Also compare Gildemeister and Hoffmann, Die atherischen 

 Ole, 2«* Ed. 1. 585. 



2 ) Report October 1904, 82. 



z ) Berichte von Roure-Bertrand Fils, April 1911,11. 



4 ) Pharm. Ztg. 46 (1901), 277; Report October 1901, 47. 



