2G6 Analysis of Air taken from an Ice-Honse. 



will be useless. Every calculator at all practised in this kind 

 of calculation, will still find other methods for abridging the 

 little calculation of the quantities x and rf/ : all these little arti- 

 fices, as well as the demonstrations of these expressions, are too 

 easily found to require my dwelling upon them longer. 



When tile altitudes of the pole-star are taken with a reflect- 

 ing sextant, or with a non-repeating instrument, and even with 

 a repeating circle if the observations are not carried beyond 

 from four to six repetitions, the correction dz, which is very 

 small, may be neglected, keeping merely to the last two equa- 

 tions ( 1 ). 



L. Analysis of Air taken from an Ice-House. By John Mur- 

 ray, F.L.8. M.G.S. M. W.S. Sfc. Sfc. 



To the Editors of the Philosophical Magazine and Jou)-naL 



M9th July, 1822. 

 R. Parker of Sweeney Hall, near Oswestry, 

 having erected an ice-house on a construction which seems well 

 adapted for the preservation of ice, mentioned to me that the 

 included air was incapable of supporting comlnistioii ; and that 

 the person employed felt great difficulty in breathing, and re- 

 quested me to analyse it. As it presents some curious pheno- 

 mena, perhaps you will do me the favour to give insertion to an 

 account of it. 



On the 24th of May last, at 1 1 a.m., the temperature of the 

 atmosphere under the thatched roof above the ice-house was 

 61" 5' Fahrenheit ; while in the ice-house itself the thermometer 

 indicated 63" 5' Fahrenheit, almost in contact \vith the ice ! ! 



A candle let down, no sooner entered the dome than it was 

 extinguished. A bucket was then lowered down, and being 

 drawn up again, it was found to contain an atmosphere which 

 immediately extinguished a candle. 



Two phials with glass stoppers, accurately fitted and filled 

 with water, were emptied in the ice-house ; and the stoppers 

 further secured by slips of bladder tied over them : their con- 

 tents were subjected to a careful analysis. A glass tube con- 

 taining a cubic inch, and graduated into 100 parts, was filled 

 with this air over water : a chip of jDure caustic potassa being 

 introduced and agitated therein absorbed 5 parts. The resi- 

 dual air being afterwards brought in contact with nitrous gas, 

 16 parts more were absorbed by water. In a subsequent ex- 

 periment 32 parts of hydrogen were added, and exploded by 

 the electric spark. The remaining air, after being agitated in 



contact 



