( 111 ) 
M. Amontons , a Member of the Academy of 
Sciences at ‘Paris , alfo relates in the Memoirs of 
that Academy of the Year 1704, that thisExpanfion 
of the Mercury , is but ttt Part of its Bulk from the 
greatefl: Heat to the greatefl: Cold that is felt at 
' Paris . For my own part, I found in the great 
Cold, we had here this Winter on the if- January 
laft in the Morning, that the Bulk of the Mercury 
tvas condenfed almofl: 5 A 0 Part of the Extent it had in 
boiling Water. The Cold we had that Day, the 
Wind being at Eaft, was one of thefevereft that ever 
was felt here. 1 fliall give you a more exadt Account 
of it hereafter, when I have compared my new 
Thermometers with thofe ordinary Ones I made ufe 
of for thefe four or five Years paft. My new Ther- 
mometers of Mercury I had made of a good large 
Size, and in fuch Manner that, having divided in 
each the whole Quantity of Mercury it contains 
into one hundred thoufand Parts ; and having 
mark’d the Extent of the bulk of that Mercury in 
boiling Water, 1 can at any time fee on the Divisions 
of thefe Thermometers, by how many Parts the 
Bulk of the Mercury is condenfed through the pre- 
fent Temperature of the Air. And though I have 
made four of thefe Thermometers, which differ ve- 
ry much as to their Size, and the Quantity of Mer- 
cury they contain, yet they agree within a very 
few of thefe Parts. As pure Mercury is of the 
fame Nature every where, nor is liable to any alte- 
ration from being enclofed in a Tube; and as it is 
probable, that taking it equally purified, it will in 
different Countries be fubjedt to the fame Expanfion, 
if expofed to the fame Degree of Heat ; for this 
Reafon 
