318 Dr. A. von Planta and Mr. "W. Wallace an Apiine. 



Strong nitric acid dissolves apiine in the cold without decom- 

 position, and it is ])recipitated nnchanged by jjouring the solu- 

 tion into cold water. 



VI. Action of Heat. 



0'346 grm. of pure apiine was dried in ^ water-bath until no 

 further loss of weight was observed. It then weighed 0-332 grm., 

 giving a loss of 0-014 grm. It was now exposed to the air for 

 several hours, M'hen it was found to have regained its original 

 weight exactly. 



From these and other experiments it appeal's that 100 parts 

 of apiine, dried at 212°, absorb from the atmosphere a determi- 

 nate quantity of hj'^grometric moisture, amounting to 4-31 parts ; 

 and further, that it does not lose any portion of this under the 

 air-pump over sulphuric acid. 



For the purpose of determining its melting-point, 0-3323 grm. 

 was heated in the air-bath to 110° C. (230° F.) for ten minutes; 

 after cooling, its weight was found to be the same. The same 

 portion was then heated for ten minutes to 120° C. (348° F.), 

 and the weight still remained unaltered. 



Raising the heat by slow degrees, it was found to melt at 

 180° C. (356° F.). At 300°, or between that and 212° C, it 

 began to decompose. When apiine is bui-nt on a platina knife, 

 it emits an odour resembUng that of charring sugar, but more 

 pungent. 



^Vhen exposed to the flame of a spirit-lamp, it first melts, then 

 becomes yellow, and subsequently brown, and after evolving 

 some gaseous matters takes fire, and burns for a short time with 

 a smoky flame, leaving a bulky residue of charcoal, which burns 

 away with some difficulty. 



The following experiment was made in order to ascertain 

 whether apiine could be fused viathout undergoing alteration. 



0-193 grm., previously dried in the water-bath, was heated in 

 a shallow platinum capsule until completely fused. The pro- 

 duct was clear and transparent like glass, and of an amber tint. 

 On cooling, it cracked and split like gum. It then weighed 

 0-188 grm., having lost 0-004 grm., which may be accounted 

 for by a very slight incipient decomposition. Had it lost 1 equiv. 

 of water, the decrease of weight would have amounted to about 

 0-008 grm. 



This shows that a])iine is capable of being fused without de- 

 composition ; and further, that it cannot be made to give up any 

 of its water, or rather the elements of water, by heat, without 

 complete destruction of its identity. This is a somewhat cha- 

 racteristic property, and serves to distinguish it from many other 

 substances. 



