THE TECHNOLOGIST. [Feb. 1, 1865. 



324 ESSENTIAL OILS FROM 



muted crystalline character. Heated carefully per se, it melts, and 

 emits the odour of putrifying meat, which is followed by empyreumatic 

 vapours. It melts at 262-4° F. In water it is but little soluble, 1 part 

 requiring 600 parts to dissolve it ; but even this quantity imparts a 

 bitter taste 'to the water. Ether and boiling alcohol both take it up ; 

 the solution in the latter giving an alkaline reaction. It is very soluble 

 in chloroform, sulphide of carbon, and oil of turpentine, also in dilute 

 and concentrated acids. M. Zeyer has obtained for this substance the 

 formula C 30 H 20 N0 5 . 



Its physiological effects have not as yet been subjected to investiga- 

 tion. 



The extract prepared from the decoction of this bark, produced while 

 operating upon it in the still, contains, judging from M. Zeyer's analysis, 

 the new alkaloid and tannic acid, or rather a peculiar variety of that 

 acid, together with most of the other organic substances enumerated 

 above, with the exception of the resin, which boiling water alone is not 

 capable of separating from the woody portion of the bark left in the 

 still. 



In concluding this account of. the" 'Atherosperma moschatum, it is of 

 interest to draw atlentiou to the fact, that this tree belongs to the 

 Monimiacese, a family of plants largely represented in South America, 

 and also found in Asia and Australia ; but from which, until the pre- 

 sent time, no drug has been procured. 



Prostanthera lasianthos. — This species of Prostanthera is widely dis- 

 tributed, and is one of the most common of the smaller trees met with 

 in the forest valleys of Victoria and Tasmania, as also in a portion of 

 New South Wales. The oil is procured from the leaves, which, should 

 its medical properties bring it into request, could without difficulty be 

 obtained in large quantities for distillation. The oil is a limpid, green- 

 ish-yellow fluid, of a mint-like odour, and rather mild mint-like taste ; 

 the after-taste is not disagreeable. The specific gravity of this fluid is 

 0*912, and the yield from 100 lbs. of fresh leaves is 2 ounces 4\- drachms. 

 It is worthy of remark, that this plant is one of the few species of the 

 comprehensive order of Labiatce, which attains to large arborescent 

 growth. 



Prostanthera rotundifolia. — This plant is of a shrubby character, and 

 is not so common as that which has just been noticed. It yields an oil 

 which resembles that from theP. lasianthos both in smell and taste. 

 In colour it is darker, and its specific gravity is also considerably higher, 

 being 0941. The yield from 100 lbs. is 12 ounces. 



Mentha Australis. — This plant and the two following are true mints ; 

 they do not exceed the size of herbs, or half shrubs. They are all 

 available in very considerable quantity in Victoria, and are also found 

 in New South Wales, South Australia, and Tasmania. Of the Mentha 

 Australis three samples of oil were forwarded to the Exhibition of 1862. 

 It is procured by the distillation of the herb ; and as the leaves do not 



