1823.] Mr. Chamberlain on Napthalin^t 137 



When napthaline is added to the last mentioned fluid, its 

 temperature sunk from 65° to 57^°, and the best method of 

 causing the solution to crystallize is the following : Dissolve as 

 much napthaline in a quart of oil of turpentine as it is capable of 

 taking up by agitation ; then add about two ounces more naptha- 

 line, and dissolve it in the oil with the assistance of heat. Set 

 the solution in a very cool place to crystallize ; in this way long 

 prismatic crystals terminated by pyramids will be procured. If 

 the fluid poured off* after the formation of these prismatic 

 crystals remain in a cool place, large hexagonal plates may 

 be obtained. To obtain a honeycomb mass, differing from 

 that formed by sublimation only in the greater thickness of the 

 partitions, pour off" the fluid from the plates obtained as above, 

 after they have been forming for at least 48 hours ; set it 

 aside to crystalhze, and in a few days, the honeycomb mass will 

 be procured. 



It is very entertaining to watch the fluid when crystallization 

 is commencing. Minute particles are seen passing from one 

 part of the vessel to another ; sometimes a crystal will be per- 

 ceived to increase suddenly in size ; it will then circulate 

 through the whole of the fluid with great rapidity, and afterwards 

 approaching another similar crystal, they will for some time 

 mutually attract each other ; but as soon as they come in con- 

 tact, both are violently repelled to a considerable distance ; 

 after a time attraction recommences ; they again approach each 

 other, and are again repelled ; the repulsive power lessening after 

 every contact, they eventually unite. 



Tn this way several prismatic crystals may be observed under- 

 going alternate and mutual attraction and repulsion, and event- 

 ually forming the radii of a hexagon, which is by degrees com- 

 pleted, and becomes a regular hexagonal plate. 



The action of nitric acid upon napthaline is peculiar ; when 

 they are triturated together, a butyraceous compound is formed, 

 which smells exactly like new hay. If the acid be used in con- 

 siderable quantity, a great number of small spiculae, which have 

 the appearance of a salt, are seen floating in it. It might be 

 supposed that they are crystals of nitrate of ammonia, but this is 

 not the case, for they are nearly tasteless, and difficultly soluble ; 

 but their true nature I have not yet determined. 



