616 KEPORT — 1903. 



name of heliotropin. Investigations by the author have facilitated this con- 

 version and very considerably reduced the cost of production of heliotropin. 



The conversion of safrol to vanallin by treatment with sodium methylate and 

 subsequent oxidation is also interesting ; the chief source of vanillin is, how- 

 ever, eugenol, obtained from oil of cloves. Eugenol is associated in oil of cloves 

 with a sesqui-terpene, cariophylene, from which the author has recently obtained 

 an acid containing eleven carbon atoms. 



(III) A process of expression is used for the extraction of oils which are 

 decomposed by steam, such as bergamot (linalool acetate). The artificial 

 preparation of this ester presents considerable difficulties, as linalool undergoes 

 decomposition or isomerisation on coming in contact with acids and gives only 

 very small yields of the desired esters, but investigations by the author have led 

 to its manufacture on a commercial scale. A laboratory method whereby the 

 difficulty may be overcome, worked out by the author, was also described, and 

 consisted in treating a pyridine solution of the alcohol with the required acidyl 

 chloride. The investigator of linalool has hitherto laboured under the difficulty 

 that no solid derivative of this alcohol could be obtained. It is hoped that the 

 author's recent preparation of a crystalline compound of linalool — the hexanitro- 

 dipheuylurethane — will be of assistance in this direction. Geraniol, an isomer of 

 linalool, is important as the chief ingredient of otto of rose. Its acetic and 

 butyric esters are also valuable as scents. 



(IV) A I'ourth and very ancient method for the extraction of essential oils is 

 illustrated by jasmine oil, which is obtained by exposing the flowers over odoui'less 

 petroleum, whereby the perfume is absorbed and subsequently extracted with 

 acetone. This oil is a mixture of a number of compounds, the distinctive odour 

 being, however, due to jasmone, which is present to only a small extent in the 

 oil. Peach oil contains also a large number of constituents ; among these the 

 author has isolated the ethyl ester of an undecylenic acid, the presence of which is 

 interesting as being a case of the natural occurrence of a fatty acid containing an 

 odd number of carbon atoms. 



The sesquiterpene alcohol, santalol, from sandal-wood oil, irone from orris 

 oil, the oxygenated products from orange oil, lemon oil, and lime oil were briefly 

 discussed. The specimens of these various compounds illustrated their valuable 

 properties as perfumes. A few brief remarks throughout the paper illustrated the 

 costliness of these oils ; thus it was shown that about three tons of roses were 

 required to yield 1 lb. of otto, the cost of peach oil is between three and four 

 times as great, whilst to prepare 1 lb. of jasmone about 200 tons of jasmine 

 flowers would be required. 



8. The, Cholesterol Gro%vp. By R. H. Pickard, D.Sc. 



Numerous compounds of the empirical formula C.^-Hj^O have been described and 

 have all at some time been called cholesterins or cholesterols. Only a few of these 

 have been well characterised, and their separate identity requires further proof. 



The best known of these compounds, ' animal cholesterol,' of which the best 

 source is human gallstones, is a very stable compound. The presence of an 

 hydroxyl group, of at least one asymmetric carbon atom, and of an ethylene 

 linking in the cholesterol molecule have been proved. The molecule is composed 

 of a normal chain of nineteen carbon atoms attached to a complex nucleus. 



Attempts to reduce cholesterol by chemical means were unsuccessful, but a 

 dihydrocholesterol has been separated from human faeces. 



9. On Acridincs. By Professor A. Sexier, Ph.D. 



I. Acridines, 



In 1871 Graebe and Caro isolated from crude anthracene a yellow crystalline 

 base, which on account of its irritating action on the skin and mucous membrane 

 was named acridine. The base when in solution exhibited a beautiful blue 



