May 1, 1865.] THE TECHNOLOGIST. 



ON THE USE OE COCA LEAVES. 467 



smell will not recommend it to those who judge by these tests ; but, as 

 I before stated, neither of these objections will affect the watch, and 

 possibly both could be removed by some process, with which I am 

 unacquainted, without destroying its good properties. I therefore give 

 the preference to animal oil, for from it I obtain a really excellent 

 watch-oil. I have not arrived at that conclusion from any preconceived 

 notions of its superiority, but from the results arising from my various 

 experiments. My great objection to nut oils, and more especially to 

 hazel oil, is their tendency to cause rust. Nut oils have a good look, 

 a nice smell, and a fine taste ; bury them in snow, and they will come 

 out as liquid as when put in ; use them on watches, and at the end of 

 twelve months they are either getting thick or very red in colour, thus 

 indicating an early stopping of the watch. 



The methods of preparing watch-oil are numerous and diversified ; 

 what the best mode is I am not prepared to say. For nitration, I pass 

 the oil through either blotting-paper or charcoal. To remove the acid, 

 some use lead filings, others carbonate of soda mixed with distilled 

 water. The fatty matter is generally taken out by freezing and again 

 filtering to purify it ; some boil it in water, some in alcohol. In 

 endeavouring to procure a good watch-oil, I have given up all hopes of 

 being able to make an oil to please every watchmaker. This is 

 impossible, owing to the grounds on which they base their judgments. 

 Oil may be rendered bad by other causes entirely independent of any- 

 thing connected with the oil ; as, for instance, there are certain kinds 

 of brass which will destroy the quality of good oil. Cedar-wood, if 

 used for any part of a clock-case, will cause every oil applied to the 

 movement to thicken in a few months. 



ON THE USE OF COCA LEAVES. 



BY DR. ABL, OF ZARA * 



The Novara expedition enables me to speak of one of the most proved 

 narcotic substances, well qualified to become to soldiers and sailors as 

 faithful a companion as tobacco is now. 



It is the coca, the leaves of different varieties of Erytliroxylon coca, 

 Lam., a shrub which is cultivated to a great extent in South America, 

 especially in Brazil, Bolivia, Peru, Ecuador, Venezuela, New Granada, 

 Guiana, as well as in the East and West Indies. These leaves have 

 rather a good taste, and several very distinguished travellers, as Poppig 

 (see Sir William Hooker's " Journal of Botany'), Weddell, Von Martius, 



* From an article on Troops' Beverages, in the "Austrian Military Journal.' 

 Translated by "E. Goeze. 



