582 l'HILOSOl'HICAL TRANSACTIONS. [ANNO 1784. 



such a form as they could not have assumed without fresh water superadded and 

 frozen on them, for the cavities between them were partly filled with new ice. 

 I endeavoured to take the ice out with my fingers, but in vain ; and it was with 

 some difficulty I could force it asunder even with a pointed knife, to get at the 

 thermometer piece. When that was got out, great part of the coiled wire was 

 found enveloped in new ice. The passage through the ice to the stem of the 

 funnel, which I had made pretty wide with a thick iron wire red-hot, was so 

 nearly closed up, that the slow draining off of the water was now sufficiently 

 accounted for, and indeed this draining was the only apparent mark of any pas- 

 sage at all. On taking the ice out of the tunnel, and breaking it to examine 

 this canal, I found it almost entirely filled up with ice projecting from the solid 

 mass in crystalline forms, similar in appearance to the crystals we often meet 

 with in the cavities of flints and quarzose stones. 



If, after all these circumstances, any doubt could have remained of the ice in 

 question being a new production, a fact which I now observed must have removed 

 all suspicion. I found a coating of ice, of considerable extent and perfectly 

 transparent, about a 10th of an inch in thickness, on the outside of the funnel, 

 and on a part of it which was not in contact with the surrounding ice, for that 

 was melted to the distance of an inch from it. Some of the ice being scraped 

 off from the inside of the funnel, and applied to the bulb of the thermometer, 

 the mercury sunk from 50° to 32°, and continued at that point till the ice was 

 melted ; after which, the water being poured off, it rose in a little time to 47°. 



Astonished at these appearances, of the water freezing after it had been 

 melted, though surrounded with ice in a melting state, and in an atmosphere 

 about 50°, where no part of the apparatus or materials could be supposed to be 

 lower than the freezing point, I suspected at first that some of the salt of the 

 freezing mixture might have got into the water, and that this, in dissolving, 

 might perhaps absorb, from the parts contiguous to it, a greater proportion of 

 heat than the ice of pure water does. But the water betrayed nothing saline to 

 the taste, and I had applied the freezing mixture with my own hands, with great 

 care, to prevent any of it being mixed with the water. To remove all doubts 

 however on this point, I purposed repeating the experiment with some pieces of 

 the ice I had stored up in the cellar, to see if this would congeal, after thawing, 

 in the same manner. But going to fetch the ice, and examining it in the cask 

 in which it was kept, I was perfectly satisfied with the appearances I found there; 

 for though much of it was melted, yet the fragments were frozen together, so 

 that it was with difficulty I could break or get out any pieces of it with an iron 

 spade ; and, when so broken, it had the appearance of breccia marble or plum- 

 pudding stone, for the fragments had been broken and rammed into the cask 

 with an iron mall. 



