(J40 MR THOMAS GEORGE TILLEY 



suggesting the idea of great volatility. When heated it becomes yellow, and 

 deposits brown flakes ; it begins to boil at 255 C Fah. ; the temperature quickly 

 rises to 400 and, the fluid begins to boil very rapidly at about 430. At 440 a 

 pure colourless oil distils over, and the boiling fluid does not gain any heat for 

 some time. At this period the receiver was changed, and the oil coming over 

 between 440 and 442 obtained. 



To purify this portion of the oil, it was distilled again ; and, after having 

 stood some time in contact with melted chloride of calcium, it was once more 

 rectified. 



To ascertain the composition of this oil, it was burned with peroxide of 

 copper, when 



.2960 of substance gave .3082 water, 



= .0334 Hydrogen, and 1.228 Carbonic Acid, 



= .28281 Carbon. Carbon being 76.437 a. w. 



which numbers give per cent., 



Carbon, 88.10 

 Hydrogen, 11.29 



and these per-centage numbers lead to the formula C 10 H 16 , the numbers calcu- 

 lated from this formula being, per cent., 



Carbon, 88.46 

 Hydrogen, 11.54 



The numbers found agree so nearly with those deduced by calculation from 

 the formula given, that there can be no doubt but that the Oil of Grass contains, 

 and chiefly consists of, a carbo-hydrogen, in which the proportion of the carbon 

 is to that of the hydrogen as 10 to 16, as in the case of oil of turpentine, and other 

 volatile oils of the same class. 



The oil appears to be rendered impure by a certain quantity of a resin, pro- 

 bably formed by the absorption of atmospheric oxygen. 



Subjected to the action of powerful oxidizing agents, it is converted into re- 

 sinous, adhesive bodies, having acid properties, and dissolving in alkalies, giving 

 red solutions. Perzoz' oxidizing fluid, formed by dissolving bichromate of potash 

 in dilute sulphuric acid in equivalent proportions, converts the oil into a glutinous 

 dirty resin. Nitric acid acts with great violence on the oil, and produces, even 

 after the continued application for several days of the strongest acid, only a yel- 

 low resin. 



The Oil of Grass combines with hydro-chloric acid, forming a yellow oil, 

 heavier than water, and not yielding crystals by the application of intense cold, 



