ON CONSUMPTION OP FUEL AND PREVENTION OP SMOKE. 101 



probably those of Dr. Thomson and Mr. Mushet; several others have inves- 

 tigated their chemical composition, but the discrepancies which exist in the 

 varied forms of analysis render them of little value when applied to the useful 

 arts. Dr Thomson examined four distinct species of coal, of which the 

 following are the results : — 



Dr. Ure also supplies an analysis of splint and cannel coal, which differ 

 from those experimented upon by Dr. Thomson, as follows : — 



Quality. 



Splint coal.. 

 Cannel coal 



Specific 

 gravity. 



1-266 

 1-228 



70-90 

 72-22 



Hydrogen. 



4-30 

 3-93 



2-8 



Oxygen. 



24-80 

 21-05 



The chief difference between the experiments seems to consist in the in- 

 creased quantity of hydrogen in Dr. Thomson's cannel coal, and the total 

 absence of oxygen, which in Dr. Ure's specimens were found in excess. 



The next authority is Mr. Mushet, who analysed nearly the whole of the 

 Welsh coals, and some others, of which the following are selected, viz. 



Again, we have some of the American anthracites with upwards of 90 per 

 cent, of carbon and 3-6 of volatile matter, which correspond with nearly all 

 the other descriptions of anthracites as given by Mr. Mushet, and more 

 recently by Dr. Kane in his excellent work ' On the Industrial Resources of 

 Ireland.' 



In addition to the above, Dr. Fife has given some valuable experiments on 

 coal, wherein he does not materially differ in the bituminous qualities from 

 those of Mr. Mushet. The results of Dr. Fife's experiments were found to 

 be in the bituminous and anthracite kinds. 



It will be observed from these experiments that considerable differences 

 exist as to the quantity of carbon contained in each sort, and provided it be 



