122 Mr. Pritchardf on an Easy Method of [Aug. 



lay immediately beneath, were inflamed on coming in contact 

 with it. I was standing by when it suddenly burst into 

 flame, and I thought, at the time, had the melted rosin 

 been permitted to drop into water, or had it fallen to such 

 a distance as not to be kept liquid by the radiant heat from 

 the red hot mass above, that there would have been no 

 flame, but silent combustion. 



I have since learned from Mr. Price, in whose distillery 

 it has always been the practice to put the unstrained turpen- 

 tine into the still, that he was well aware of the fact which 

 it is the object of this paper to record, from a fire having 

 occurred several years ago on his premises, when in the 

 possession of his predecessor, Mr. James Price, and that, 

 ever since, they cool down the chip cake, immediately on 

 removal from the still, with water, and afterwards use it as 

 fuel under the still. 



An instance of spontaneous combustion occurred with my 

 friend Mr. Philip Coffey, of the Dock Distillery, which 

 is worth relating while on this subject. 



He had made a quantity of the mixture used in theatres 

 for producing red light, a powder consisting of nitrate of 

 strontian, sulphur, chlorate of potash, and sulphuret of 

 antimony, with a little lamp-black. A paper parcel of this 

 '' red fire, " of about a pound or two by weight, was left by 

 him on a shelf in a store-room where there was no fire nor 

 candle light ; the following day, while reading in an adjoin- 

 ing room, he perceived a smell as if some of this powder 

 were burning, and, on examination, he found it had ignited 

 spontaneously on the shelf and was actually consumed. 



M. SCANLAN. 



Sir John Rogersons Quay, Dublin, 

 29th June, 1835. 



Article V. 



On an easy method of measuring Prismatic Spectra. By 

 Mr. Andrew Pritchard. 



It may be questioned whether any important discovery 

 relating to the prismatic spectrum formed by decomposing 



