218 



ODOROGRAPHIA. 



therefore bears the same relation to menthone as l3orneol to 

 camphor.* 



Menthyl chloride, C\o H^g Ci. was obtained by Walter by 

 the action of phosphorus pentachloride on menthol, while 

 Oppenheim prepared it by heating with hydrochloric acid. It is 

 also formed by the combination of menthene with hydrochloric 

 acid, and is a liquid which has a pleasant odonr rescmUing that of 

 mace, and a refreshing taste. It boils with decomposition at 

 204^ C. 



A mint possessing a very sweet and delicate odour of peppermint 

 is the Mentha pulegium var. Gibraltarica. It is cultivated 



Mentha pulegium, 



var. Gibraltarica ad nat., from a plant grown in England. 

 Natural size, and showing leaf and flower magnified. 



in many English flower-gardens as a border plant or for " carpet 

 bedding " on account of its pale, bright-green colour, and its close, 

 neat habit of growth. As this plant is not quite sufficiently hardy 

 to withstand the English winter if left in the open ground, it is 

 usual to preserve a stock in cold frames. It will bear rapid forcing 

 in the early spring, and seems to revel in strong heat and moisture. 

 It is one of the very easiest plants to propagate, so much so that 

 it is hardly necessary to talk about taking cuttings, as its growth 



* Atkinson and Yoshida, Journ. Cheni. Soc, 1882, p. 49. 



