296 Messrs. B. Silliman and H. Wurtz on Flame Temperatures, 



Table II. 



For equal volumes of the gases burning 

 in air. 



Calorific effects in 



heating liquid 



water. 



Calorific effects 

 above 100° C. 



Centi- 

 grade 

 degrees. 



Fahren- 

 heit 

 degrees. 



Centi- 

 grade 

 degrees. 



Fahren- 

 heit 

 degrees. 



f (specific heat HO = -4805)... 



Hydrogen \ (specific heat HO=4750)... 



[ (mean) 



3192 

 3204 

 3198 

 2996 

 2660 

 2916 



5778 

 5799 

 5788 

 5425 

 4820 

 5481 



2744 

 2755 

 2749 

 2996 

 2414 

 2743 



4971 

 4991 

 4980 

 5425 

 4386 

 4970 



Carbonic oxide 



Marsh-gas (specific heat HO = -4805) ... 

 Olefiant gas (specific heat HO = '4805)... 



Computation of Calorific Effects of Mixed Gases. 



The above Table renders the calculation of the calorific effects 

 of any given gaseous mixture, whose centesimal composition is 

 known, a matter of extreme simplicity. It is only necessary to 

 obtain the sum of the multiples of the percentage of each com- 

 ponent gas into its calorific capacity, as given in this Table, and 

 divide by 100*. 



To serve as examples of these modes of computation, we 

 here cite, in tabular forms, the results of some analyses of a 

 number of gaseous mixtures made by us during the past winter 

 (1868-69). [These analytical results, it may be remarked, 

 possess points of novelty and importance, both scientific and 

 practical, which will bring them up again hereafter in other con- 

 nexions. They are here placed on record.] 



Table III. gives the results of two analyses of gaseous mixtures 

 obtained by passing steam superheated to incandescence upwards 

 through a mass of anthracite coal heated to a high degree in a 

 clay retort of a novel construction, according to what is now 

 known as the " Gwynne-Harris," or American Hydrocarbon 

 Gas System. In this Table the results are calculated without 

 carbonic acid and sulphuretted hydrogen, which, with traces of 

 nitrogen and sometimes of oxygen, are found in the unpurified 

 anthracite gas. 



* Professor Bunsen, in the masterly discussion of the subject presented 

 in his ' Gasometry,' not having in view the exact object we propose, has 

 used a train of reasoning and a mode of formulation of some complexity, 

 to follow which requires some little mathematical skill, — part of his object 

 having been to construct a formula so general and comprehensive as to 

 cover the direct computation, from any gaseous mixture independently, of 

 its special calorific intensity. We have here aimed at so simplifying as to 

 bring the wnoie subject within the capacity of all. Our above tabulation 

 of the individual gaseous components, as a starting-point, seems to us to 

 accomplish this most effectually, so far as illuminating gases are concerned. 



