1862.] 



on Mauve and Magenta, 



475 



Charge each of our type-moulds with an atom of phenyl, and you 

 accomplish the construction of phenylated hydrogen, phenylated 

 water, and phenylated ammonia, 



Ph 



H 



Ph 



H 







Ph 



WE 



substances better known as benzol^ phenol, and aniline;* and the 

 existence of which in coal-tar-oil I have already pointed out to you. 



But it is time for us to return to the point from which we started. 

 What has the recognition of our types to do with the distillation of coal? 

 In what manner do they explain the formation of the variety of sub- 

 stances generated in this process. In coal we have the elements of the 

 three types of matter, and we find that hydrogen, water, and ammonia 

 are in fact produced to a very appreciable extent during its distillation. 

 The quantity of free hydrogen is generally small ; moreover, mixed as 

 it is with the carbonetted hydrogens of coal gas, its presence among the 

 products of distillation of coal is not easily demonstrated by experi- 

 ment. Water and ammonia, on the other hand, are abundantly gene- 

 rated, and nothing is easier than to exhibit their production. In fact, 

 the coal-tar-oil which we have produced in our distillation-experi- 

 ment, is covered, as you observe, with a layer of water, and the appli- 

 cation of test-papers to the latter shows that it contains a large amount 

 of ammonia. Now consider that our types are generated from coal 

 in the presence of large quantities of carbon and hydrogen, two ele- 

 ments which, in proportions varying to an almost unlimited extent, 

 may aggregate under the influence of heat to compound atoms similar 

 to ethyl and phenyl ; remember, moreover, that these atoms are 

 capable of displacing, partly or entirely, the hydrogen of our types, 

 and you will realize without difficulty the number of compounds which 

 may be formed by the distillation of coal ; I say which may be formed, 

 for the diagram which I have exhibited to you enumerates only the 

 bodies which have actually been obtained ; but every day brings forth 

 new substances. It is obvious that the nature of the compound atoms 

 generated must, in a measure, depend upon the composition of the coal 

 distilled. The composition of coal, however, varies between very 

 considerable limits. In the subjoined diagram I give you a synopsis 

 of the results obtained in the analysis of several specimens of coal. 



Large specimens of these three substances were exhibited upon the table. 



2k2 



