48 Dr. Kane's Contrihutio7is to the Histm'y 



rectification of the difFerent quantities of p\'roxylic spirit used 

 in the foregoing and subsequent experiments, 1 had an op- 

 portunity of collecting a certain quantity of that oil, to the 

 presence of which I have had already occasion to allude. The 

 quantity, although very small, allowed the determination of 

 some of its most remarkable characters and of its composi- 

 tion. 



This oil is colourless when first procured ; by exposure to 

 the air and to hght it becomes coloured. Its odour is aromatic 

 and resinous. Although, as we have seen, readily passing over 

 in vapour with pyroxylic spirit at the temperature given by 

 a water-bath, yet alone its boiling-point is very high. The 

 quantity in my possession was, however, too small to allow of 

 my determining it exactly. This oil is very light; it floats not 

 only on water, but on every mixture of pyroxylic spirit and 

 water by which it is not dissolved. The oil, having been 

 purified from spirit by distillation, and from water by contact 

 with chloride of calcium, gave the following analytical results: 



From 0*388 material were obtained, 



Water = 0-377 



Carbonic acid = 1'176; 

 from whence follows the composition : 



Carbon = 83*78 or, 20 atoms carb. = 84*18 

 Hydrogen 10 79 30 atoms hyd. 10*32 



Oxygen 5*4'3 1 atom oxy. 5*50 



100*00 100-00 



A second analysis was made a few days afterwards with the 



same oil, but which had in the interim become coloured by 



the action of the air. 

 0*335 material gave 



100*00 100*00 



It thus appears that in the interim the oil had absorbed 

 half an atom of oxygen from the air. 



The formula (C20 H^q O) is the same with that obtained 

 by Fremy for resinain, from which body this oil is distin- 

 guished by its physical properties. The two substances are 

 isomeric, but as none of the combinations have been examined 

 for either, nothing can be said as to the relation between their 

 atomic weights. This oil absorbs chlorine with considerable 



