April 5, 1878.) 475 [Sadtler. 
On the Caleulation of Results in Gas-Analyses. 
By SaAmMuEL P. Saptier, Px.D. 
(Read before the American Philosophical Society, April 5th, 1878.) 
At the last meeting of the Society I promised to present a full discussion 
of the formulas involved in calculating analyses of gaseous mixtures such 
as are found exhaling from the earth in the oil-regions of Western Penn- 
sylvania and elsewhere. Iam led to do this at present, chiefly because of 
some remarks made upon this subjeet by Prof. Henry Morton, in an article 
in the ‘‘American Gas-Light Journal’’ of Feb. 16th, 1878. Otherwise I 
should have deferred a discussion of the subject until I should have com- 
pleted some absorption-tests upon the gases and analyses of portions of the 
gaseous mixtures withdrawn by such absorptions. This complete discus- 
sion of the subject I promised in a verbal communication made to the So- 
ciety at its meeting on Sept. 21st last, mention of which is made on page 
11 of No. 100 of the Proceedings. 
In the article of Prof. Morton alluded to, he shows that the eudiometric 
combustion of a mixture of hydrocarbons of the Paraffin series cannot give 
results capable of being reckoned into percentage composition, and refer- 
ring to my article published in the Proceedings, Vol. XVI, pp. 206 and 
585, shows that an error in my formulas enabled me to get a ‘‘solution in 
appearance where no solution was possible.’’ 
This error in the formulas I had discovered myself in the Spring of 1877, 
and I had the absorption tests which I had described at the meeting of 
Sept. 21st last made purposely to enable me to solve the question of the 
composition of the gases independently of the use of formulas. In a pri- 
rate letter to Prof. Morton, dated Dec. 31st last, in answer to one re- 
ceived from him a day or two before, calling my attention to the error, I 
acknowledged the error of the formula used by me in my printed paper, 
and mentioned that I was proposing to rectify the results as first published 
by the aid of other tests. 
With reference to the matter of the impossibility of determining the com- 
position of a mixture of gases belonging to the Paraffin or marsh-gas series, 
Prof. Morton shows very clearly in his paper that this impossibility does 
exist When we take three or more paraffins or a mixture of hydrogen and 
two or more paraffins. In this latter case the hydrogen molecule simply 
acts like a member of the series lower than marsh-gas or CH,. 
When we ask the question with reference to two members of this series, 
however, we find that a solution is not impossible. In reckoning the re- 
sults of analyses of ordinary illuminating gas, it is always necessary to cal- 
culate the relative amounts of hydrogen and marsh-gas from the results of 
the eudiometric combustion, and what is true of marsh-gas and hydrogen 
(which latter we have just said must in such eases be considered as a lower 
member of the marsh-gas series) is true of marsh-gas and ethyl-hydride or 
marsh-gas and propyl-hydride. So we may, in dealing with the mixture 
of gases which has been submitted to a eudiometric combustion, and which 
we know by previous tests and absorptions cannot contain anything else 
PROC. AMER. PHILOS. Soc. xviI. 101. 3G. PRINTED MAy 18, 1878, 
