100 IRREGULARITY OF THE PLANET SATtJRN.- 



quality, among which ftuty be reckoned the Kilkenny couL 

 abunda'Ttie *^ ne niost important difference among the< varieties of this 

 gas, the more miner*al, connected with their application as sources of light, 

 rifi^atiorT *** consIsts m ^ e quantity of sulphuretted hidrogen gas, which 

 is mixed with their aeriform products} and it unfortunately 

 happens, that the coal, otherwise best adapted to this pur- 

 pose, yields generally the largest proportion of this offensive 

 Best mode of gas. The only effectual method of purifying the coal gas 

 purifying it. f rom su iphuretted hidrogen, on the large ncale of manufac- 

 ture, will probably be found to consist in agitation with 

 quicklime and water, composing a mixture of the consis- 

 tence of cream. Simple washing with water by no means 

 effects the complete separation. 

 Condensable , j n t j ie experiments which were made on the products of 

 ed. the distillation of coal, I purposely neglected the amount 



and analysis of the condensible fluids, because they cannot 

 be advantageously ascertained by the same operation with 

 the elastic ones. They may also be much better determined 

 On the large scale of manufacture^ thauvby limited experi- 

 ments. For the same reason t was not solicitous to mea- 

 sure even the aeriform fluids ; and on this subject, I believe, 

 more accurate information has been communicated by Mr. 

 Murdoch, than it was in my power to acquire. 

 Manchester , May 19, 1808. 



m. 



Account of a new irregularity lately perceived in the appa- 

 rent Figure of the Planet Saturn. By William IIers- 

 chel, LL. D. F. R. S*. 



Singular figu.c Jj HE singular figure of Saturn, of which I have given an 

 account in two papersf, has continued, for several reasons, 

 to claim my attention. When I saw the uncommon flatten- 



* Philos. Trans, for 1808, p. 159. 

 -\ Sec our Journal, vol. XIII, p. '4. 



