110 Mr. J. Glaisher's Remarks on the Weather 



of this salt has been already described. It is soluble in water. 

 The mean of three analyses yielded the following result: — 



Chromic acid . . . 52-070 



Lime 23*990 



Potash 17-550 



Water 6-230 



99-840 



This approaches nearly to the formula 3K0 7CaO CrOg 

 5HO. When this salt is ignited it does not fuse, and when 

 cool its colour is yellow. It does not again altogether dissolve 

 in water, and thence it appears to have undergone decompo- 

 sition. 



XIV. Remarks on the Weather during the Quarter ending 

 December 31, 1849. By James Glaisher, Esq., F.R.S., 

 F.R.A.S.y and of the Royal Observatory^ Greenwich^. 



IN my paper upon the meteorological particulars of the 

 quarter ending September 30, 1849, and published in the 

 Philosophical Magazine, I spoke of the great mortality which 

 had existed throughout that quarter in London and its en- 

 virons. This excess of mortality decreased rapidly; and not 

 less remarkable has been the decrease in the weekly and 

 monthly rate of mortality in the past quarter ; the mortality 

 having been, in three successive weeks in November, 269, 284, 

 and 270 below the estimated number. The mortality in Oc- 

 tober was 557, in November was 1160, and in December was 

 564 less than the calculated numbers. This decrease is ex- 

 traordinary ; and it proves that the epidemic of cholera carried 

 off many of the sickly and weakly, whose deaths would other- 

 wise have made up the average numbers in the past quarter. 



The meteorological returns for the past quarter have been 

 furnished to the Registrar- General from the usual places, 

 and which have passed my usual examination and reduction. 



During the past quarter there has been an unusual preva- 

 lence of fog, particularly in the month of November. Snow 

 has fallen more frequently than usual, but in small quantities 

 only. The daily temperatures of the air till October ] 6 and 

 after November 20, with the under-mentioned exceptions, were 

 below their average values ; in the former period the mean 

 defect was 4°-2, and in the latter it was 4°-0. Between Oc- 

 tober 17 and November 14 the temperature was above the 



• Communicated by the Author. 



