250 REPORT ON NATIONAL MUSEUM, 1886. 



be subjectetl to not less tliaii thirty tests. As at least one day will be con- 

 sumed by each test it is plainly evident that several boilers will be re- 

 quired for the investigation in order to bring it to completion within a 

 reasonable time, and under the most ftivorable circumstances the practi- 

 cal testing of a single coal will probably occupy a week. 



^4) In the present state of our knowledge we know absolutely nothing 

 of the chemical constitution of coals, and the investigation in this direc- 

 tion will be on entirely new grounds. The work will be confined totlie 

 laboratory, and will require much patient labor. 



The combustible portion of coal consists essentially of carbon, hydro- 

 gen, and oxygen, with small amounts of other elements, especially 

 sulphur and nitrogen. In the ordinary methods of chemical examination 

 of coal there are two methods followed. In one we determine the amounts 

 of volatile matter containing nearly all the hydrogen and oxygen with 

 some carbon, and the coke, consisting of carbon with only a very 

 small amount of hydrogen and oxygen, left after heating. In the other 

 we determine the percentages of each element. Now, while results 

 obtained in this way have some value, yet they show us nothing of the 

 condition of the elements in the coal itself, as whether or not any of the 

 carbon exists in the free state in the coal, whether the volatile portion 

 exists as such already formed in the coal, or whether it is produced 

 from the decomposition of other combinations in the coal which are 

 broken up by the heat. 



By the determination of the heating power of the coals of the whole 

 country, results will be obtained which will be of inestimable value to 

 every large consumer of coal, as by them he can readily ascertain which 

 coal at his command is really the cheapest, which may or may not be 

 the one that costs the least money. 



Testing under several sets of conditions, besides allowing a much 

 wider field of application, will also show the error of using methods of 

 combustion which are not suited to the coal used. 



The results of the chemical examination will have wide application 

 in certain industries, such as the manufacture of illuminating gas, and 

 the production of coke for metallurgical purposes, while they would also 

 throw much light upon the question of gas in mines, which would give 

 them an added value from the question of human life involved. 



A careful estimate of the number of coals that it would be desirable 

 to test, places it between 200 and 250. Under the most favorable cir- 

 cumstances these would require between five and six years for thorough 

 examination. 



This estimate is based upon the use of six boilers of about 20 horse- 

 power, properly erected with the necessary attachments for controlling 

 and observing the combustion, put up in a suitable building that has 

 railway communication. 



There also will be required a biboratory for the chemical and phys- 

 ical work, ])rovided with a large amount of special ap[)aratus. 



