3 s 9 
the Congelation of Quickfilver. 
§ io. We muft now return to Europe. In the beginning 
of the year 1780, M. von elterlein, of Vytegra, froze 
quickfilver by natural cold, and lent an account of his experi- 
ment in a letter to the late Profeflor guldenstadt, then at 
Peterfburg. I obtained from Gottingen a copy of this letter 
in the original German, by the friendfhip of Sir Joseph banks ; 
and, trail dated, it is as follows : 
“ On the 4th of January, 17S0, the cold having increafed 
to - 34° that evening at Vytegra, I expofed to the open air 
tin ce ounces of very pure quickfilver, in a China tea-cup, 
“ covered with paper pierced full of holes. Next day, at eight 
in the morning, I found it iolid, and looking like a piece of 
“ caff lead, with a confiderable depreffion in the middle. On 
“ attempting to loofen it in the cup, my knife raifed fhavings 
“ from it as if it had been lead, which remained flicking 
“ ll p ; an d at length the whole feparated from the bottom 
“ of the cup in one mafs. I then took it in my hand to 
“ try if it would bend ; it was like ftiff glue, and broke 
“ into two pieces ; but my fingers immediately loft all feeling, 
“ and could lcarcely be reftored in an hour and an half by rub- 
“ bing with fnow. At eight o’clock a thermometer, made by 
“ M. LAXMANN of the Academy, flood at - 57 0 ; by half after 
“ nine it was rifen to - 40° ; and then the two pieces of mer- 
“ cury, which lay in the cup, had loft fo much of their hard- 
“ nefs that they could no longer be broken or cut into fhavings, 
“ but refembled a thick amalgam, which, though it became 
“ fluid when prefled by the fingers, immediately afterwards 
“ relumed the confidence of pap. With the thermometer at 
“ - 39 0 , the quickfilver became fluid. The cold was never lefs 
“ on the 5th than -28°, and by nine in the evening it had 
“ increafed 
