164 PKOF. O. REYNOLDS ON THE FORMATION OF 



but with no better success ; and for the time I abandoned 

 the attempt. 



What the cause of this failure was I do not precisely 

 know ; but I attribute it to some excess of alcohol in the 

 ether then used^ which was not methylated ether. That 

 this might have been the cause occurred to me about two 

 months ago. I then determined to try again, and combine 

 a spray of water with that of ether. I now obtained the 

 lightest ether which Messrs. Mottershead & Co. could 

 supply. The specific gravity of this was "717 ; and it was 

 made from methylated spirit. 



With this, somewhat to my surprise, I at once obtained 

 a deposit o£ ice even without the water spray, and with the 

 same apparatus I had previously used ; it was not, however, 

 until I used the combined spray of water and ether that I 

 obtained any thing resembling a hailstone in appearance. 

 But the first time I used this combination I obtained a 

 small but well- shaped hailstone on the end of a match 

 which I held pointed towards the spray. 



The next time I tried, however, on another day, I did 

 not succeed so well with the water as without it : when 

 using the water-spray the deposit of ice was wet or half 

 melted, while without the water I obtained a hailstone in 

 much the same manner as I had obtained before with the 

 water. 



This difference in the results on the two occasions was 

 at once explained by the different states of the air ; for on 

 the first occasion it had been cold and dry, whereas on the 

 second it was warm and saturated. With the dry air the 

 ether spray reduced the temperature so far below 32° that 

 the particles of ice did not freeze together ; the force of 

 impact was not sufficient to cause them to thaw in the first 

 instance ; and hence the water spray was necessary to keep 

 tliis temperature from falling too low ; whereas with the 



