228 ANNUAL OF SCIENTIFIC DISCOVERY. 



benzine liquid, extensively used as a valuable detergent of grease from wear- 

 ing apparel, etc. 



When coal-naphtha is submitted to the action of certain chemical bodies, 

 totally different from itself in their natiu-e, the most remarkable changes take 

 place in it ; certain of its principles unite with certain elements of its added 

 body, and compounds are pi'oduced of the most unexpected nature. 



Thus we have said that one of the constituents of tar is benzole. Now, when 

 the tar is distilled, and separated into the dead oil and the light oil, this 

 body, benzole, suffers no alteration in its nature ; its affinity for some of the 

 other ingredients of the naphtha is so great, that simple heat is altogether 

 insufficient to produce a disunion; and the consequence is, that the benzole 

 goes over with the light oil, and continues to form part of it. 



By using rather more energetic chemical means, however, the benzole may 

 be separated from the naphtha, about a pint being obtained from two gal- 

 lons. It makes its appearance as a heavy, oily substance, with very little 

 smell, and a pungent taste. When this apparently useless fluid is mixed 

 with nitric acid or aquafortis, a singular phenomenon occurs, the two sub- 

 stances, the benzole and the acid, unite, and produce what chemists call 

 nitro-benzole, a fluid precisely resembling, in smell and taste, oil of bitter 

 almonds, and extensively used in various ways, in place of the more expen- 

 sive and poisonous substance whicn it represents. 



Yet another strange transformation may be effected. Phenic add we have 

 enumerated as existing in tar; and phenic acid, like benzole, is not altered 

 during the process of distillation, but passes over with the naphtha, and 

 forms part of it. Phenic acid further resembles benzole in being of little use 

 in its pure state. When, however, it is treated with nitric acid, already men- 

 tioned, and evaporated, long pale-yellow crystals, bright and clear, make 

 their appearance, very beautiful to the eye, and intensely bitter to the tongue: 

 these are crystals of carbazotic acid. Their color has caused a solution of 

 them to be extensively used in dyeing silk; their taste has made them ser- 

 viceable in adultei'ating beer. 



Using only the multiform processes placed at his command by modern 

 chemistry, the investigator into such matters has gone on experimenting 

 upon all the compounds of this curious body, tar, and has baptized with 

 fearfully hard names the substances produced therefrom, until he has given 

 us binitrobenzol, hydrobenzamide, bi-bromide of chlorabronaphtese, and a 

 dozen other no less mystifying substances. Those above mentioned are, 

 however, the principal ones which have yet been put to any practical use. 



Who will despise the nauseous, black coal-tar now? With substances ob- 

 tained from it, we have rendered our timber impervious to rot, have painted 

 our dwellings, paved our streets, made our varnishes and water-proof gar- 

 ments, taken grease from our Sunday clothes, manured our fields, dyed our 

 silken fabrics, adulterated our beer, and flavored our soaps, sweetmeats, and 

 confectionery. Chambers's Journal. 



ON SOME MODIFIED RESULTS ATTENDING THE DECOMPOSITION OF 



BITUMINOUS COALS BY HEAT. 



The following paper has been communicated to us by Dr. A. A. Hayes, of 

 Boston. When bituminous coal is exposed, in proper vessels, to a gradually 

 increasing temperature, at a certain point decomposition commences and 



