138 H. G. SMITH. 



The optical rotation of the first fraction in a 100 mm. tube was 

 -73-85°, while that of the third fraction had been reduced to 

 - 9*4°. A larger quantity of the oil (two litres) was then distilled 

 when practically the same results and percentages were obtained. 



The constituents in the fraction 227° - 240° C. suffered slight 

 decomposition when distilled under atmospheric pressure, as 

 indicated by the odour and the darkening on keeping. When the 

 oil was distilled under reduced pressure no decomposition took 

 place. The oil when thus obtained under reduced pressure is of 

 a slight yellowish colour, having a strong taste and odour of 

 peppermint, and for commercial purposes might be used as thus 

 obtained, or, the same result may be brought about by steam 

 distillation of the fraction 227° - 240° C. When placed upon the 

 tongue it has a hot and penetrating effect, quickly diffusing a 

 sense of warmth over the chest. When taken in small quantities 

 it appears to act efficaciously in the early stages of a cold. 

 Whether it has value in this or other directions is worthy of 

 determination by the medical profession. 



The peppermint constituent when obtained as pure as possible, 

 possesses an odour of peppermint which is much more pronounced 

 when diffused, but the peppermint taste is increased exceedingly, 

 and it is also much more pungent than the oil of the fraction 

 from which it was obtained. It is most probably, owing to the 

 strong odour given by this constituent when diffused, that has 

 caused the name "peppermint" to be attached to so many different 

 species of Eucalyptus. The oil of many of these species, however, 

 does not contain the constituent in sufficient quantities to enable 

 it to be isolated, or even readily detected ; and it is probable that 

 many of theconstituents found in larger amount in some Eucalyptus 

 oils are also present in minute quantities in a great many others, 

 their characteristic odour being more readily detected in the leaf 

 than in the oil after extraction. 



The only chemical references to this peppermint constituent, 

 that I can find are in Messrs. Schimmel & Go's, semi-annual 

 reports for April 1888, and April 1890, where referring to the 



