C l6 3 ] 
near him. It had folidity enough to bear extenfion 
with thefe flrokes j its hardnefs was like that of lead, 
though fomewhat fofter ; and, upon ftriking, it 
founded like lead. When the mercury was extended 
by thefe flrokes, he cut it eafily with a penknife. 
The mercury then becoming fofter by degrees, in 
about twelve minutes it recovered its former fluidity, 
the air being then 197. The colour of the congealed 
mercury did fcarce differ from that of the fluid : it 
looked like the moft polifhed filver, as well in its 
convex part, as where it was cut. 
The next day, the cold had increafed to 1 1 2 de- 
grees, which was 7 degrees beyond what it had ever 
before been obferved at Peterfburg. The feafon fo 
much favouring, he thought it right to continue his 
purfuit, not only in further confirmation of what he 
had already obferved, but to invefligate new pheno- 
mena. In two thermometers, he obferved the fame 
fadts in relation to the congealing of mercury, as he 
did the preceding day. In the bulbs which he broke, 
the whole of the mercury was not fixed, as a very 
fmall portion, much lefs than that of the preceding 
day, continued fluid. He treated this mercury as 
he did the former ; he beat it with a peftle, he cut 
it, and every thing was thus far the fame. But he 
law a very great difference in relation to the descend- 
ing of the mercury in the thermometer, the like of 
which did not occur to him, neither in the former 
nor any of the fubfequent experiments. From the 
former ones it appeared, that the mercury in the firfl 
experiment had only defcended to 470, when it be- 
came immoveable, though the glafs bulb was not 
cracked, In the experiment of the 2 jth, it defcended 
Y 2 to 
