and the Products of its Decomposition. 85 



One part of cenanthal is poured on five or six parts of hy- 

 drate of potash, and the mixture allowed to stand in a closed 

 vessel. Heat up to 120° Cent, is produced, and the fluid be- 

 comes thick. After twenty-four hours a large quantity of water 

 is added, and all that is soluble in that fluid removed. The 

 oil which remains is mixed with a fresh quantity of water, and 

 with it distilled : it passes over exceedingly slowly with the 

 watery vapour ; and only after several days, and the evapora- 

 tion of large quantities of water, is the distillation completed. 

 The oil which passes over with the water is colourless, fluid, 

 and smells slightly like lemons. Its boiling-point is 220°, at 

 which temperature, however, it is quickly decomposed, turning 

 brown and smelling differently. It is slightly soluble in water, 

 and dissolves small quantities of that liquid ; it burns with a 

 clear flame, giving little smoke. It is soluble in alcohol and 

 aether in all proportions. 



To determine its composition, several precautions are ne- 

 cessary to ensure its perfect conversion into carbonic acid and 

 water. In the ordinary manner, with oxide of copper no re- 

 sults which agree with each other can be obtained ; and only 

 by means of free oxygen, and the simultaneous use of chlorate 

 of potash in the bulb, can the whole of the carbon be obtained 

 as carbonic acid. The same specimen analysed gave in three 

 separate experiments incompatible results. 



I. II. III. 



Carbon . . 77*69 77*09 78*37 



Hydrogen . 12*69 12*71 13*11 



numbers which are too diverse to permit of their use in cal- 

 culating a formula. Traces of carbon are also found in the 

 bulbs ; and to obviate this occurrence, the substance is intro- 

 duced into the combustion- tube in a double bulb having the 

 annexed form. 



Into a is introduced a small piece of melted chlorate of 

 potash, and the bulb b being warmed, the air is driven out 

 without heating the salt. When introduced into the combus- 

 tion-tube, the bulb is filed at c, and thus the fluid allowed to 

 escape into the oxide of copper before the combustion is com- 

 menced. Towards the end of the analysis a stream of dry 

 oxygen is passed through the apparatus. By these means 



