115 

 Notes on L — and B — Lupanin. By Sherman Davis. 



The Physiological Action of Compounds Containing Bivalent Carbon, 



By J. U. Nef. 



The Calculation of the HEATiN(i Effect of Coals from the Proximate 

 Analysis. By W. A. Noyes. 



So far as I am aware, no satisfactory formula has ever been given for the cal- 

 culation of the heating effect of coals from the amounts of fixed carbon, volatile 

 combustible matter and sulphur present. It has been generally assumed that the 

 amount of o:?ygen in coals varies so greatly that no rational basis for such a cal- 

 culation could exist. During the spring of 18!»o, Mr. J. R. McTaggart and Mr. 

 H. W. Caver made careful analyses and determined the heating effect with Hem- 

 pel's calorimetre, for six Indiana coals. Recently I have had the opportunity of 

 examining similar analyses and calorimetric tests of fifteen Pittsburgh coals, made 

 under the direction of Prof. N. W. Ford, of the University of Ohio, 



In the analyses as given, the amount of oxygen in these coals appears to vary 

 between quite wide limits. On subtracting from the total oxygen the oxygen 

 present in the form of water, however, it was found that the average amount of 

 oj-ygen of combustMe matler wan 7 .72 per cent, for the Indiana coals and 8.05* for 

 the Pittsl)urgh coals, or a general average of 7.96 per cent, and a maximum devi- 

 ation from that average of 1.23 per cent. In only one coal is the difference froru 

 the mean more than one per cent. 



Since the per cent, of hydrogen in these coals is subject to only a slight 

 variation, it follows that the combustible matters present in all of these coals se 

 far as they consist of carbon, hydrogen and oxygen, have a nearly constant com- 

 position. There should, therefore, be a nearly constant factor for this total com- 

 bustible matter. In order to calculate this factor for the coals in question it iian 

 been assumed that one-half of the sulphur is found in the volatile combustible 

 matter as calculated from the difference between total volatile matter and water 

 and that the fixed carbon is given with sutHcient accuracy by subtracting the ash 

 from the coke. In other words, the combustible matter was formed for the pur- 

 poses of this calculation by subtracting from 100 the per cents, of water and ash 



■' In calculating this result Professor Ford's figures for oxygen were corrected by adding 

 three-eighths of the weight of sulphurs, on the supposition that iron pyrites in the eoa! i« 

 burned to ferric oxide in the ash. See Jour. Am. Ch. See. XVII. 



