﻿42 cox. 



sulphur has very little heating value and will in time ruin the grate bars 

 and the boiler. The estimation of volatile combustible matter and of 

 fixed carbon is of great importance, for the relation which exists between 

 these is a means of classification 3 and a criterion for judging the steaming 

 quality of a coal. The percentage of volatile combustible matter gives 

 us some idea of the gas-producing power of the coal and from, the residual 

 fixed carbon we are able to know whether the coal is coking or non-coking. 

 It remains for us to seek out the best method of estimating these factors. 



The coals of the Philippine Islands which have thus far been discovered 

 are all non-coking. They belong to a class which was of less importance 

 when the directions for coal analysis recommended by the committee 

 appointed by the American Chemical Society 4 were made. These direc- 

 tions are in general use throughout the United States and as they embody 

 the best factors of all previous research upon the proximate analysis of 

 coal, no further discussion of the literature will be entered into. However, 

 since the appearance of these directions non-coking coals have come much 

 to the front and an accurate and uniform method for their analysis is 

 now necessar} r . The point where the suggestions of the committee are 

 least applicable is in the estimation of the volatile combustible matter. 



The method outlined by them for this determination is as follows : 



Place 1 gram of fresh, undried, powdered coal in a platinum crucible weighing 

 20 to 30 grams and having a tightly fitting cover. Heat over the full flame 

 of a Bunsen burner for seven minutes. The crucible should be supported on a 

 platinum triangle with the bottom 6 to 8 centimeters above the top of the burner 

 The flame should be fully 20 centimeters high when burning free, and the determi- 

 nation should be made in a place free from drafts. The upper surface of the 

 cover should burn clear, but the under surface should remain covered with carbon. 

 To find volatile combustible matter subtract the per cent of moisture from the 

 loss found here. 



In a recent paper 5 on "Philippine Coals and their Gas-Producing 

 Power," when discussing certain analyses the following paragraph, which 

 shows that the above directions give uncertain results in the determination 

 of volatile combustible matter in Philippine coals, appeared: 



The coal analyses were made according to the directions recommended by the 

 committee appointed by the American Chemical Society. -In the determination 

 of volatile combustible matter, it has been found that in following these very 

 inaccurate results were obtained. The committee states that the most serious 

 objection brought against their method is that the rapid heating causes mechanical 



3 Hilt, C. : Jahresb. ueber die Fortshritte d. Chem. (1873), 1086. "It is neces- 

 sary for the present at least that the classification of our coals be made on a 

 basis involving the relation of the volatile and the fixed combustible matter, since 

 we have no data other than proximate analyses." 



4 J. Am. Chem. Soc. (1899), 21, 1116; The Coal & Metal Miner's Pocket Book, 

 7th ed. (1902), Scranton, Pa., 173. 



5 Cox, A. J.: This Journal (1906), 1, 890. 



