212 E. M. Walton—Liquefaction and Cold produced 
Equivalent weights were taken, seventy grams being used at 
first, but this was afterward increased to one hundred grams. 
From the following observations it will be seen that the 
amount of radiation and convection is so small that it may be 
disregarded : 
Mixture of Mn(NO,),.6H,O with Na,CO,.10H,O. Tempera- 
ture of water of calorimeter, 18° C. 
Time 
4 Temperature. 
0 min. 19°C. 
4 — 9° 
5 —10° 
6 —10°5° 
10 —10°5° 
ii —10° 
a — 7 
25 — 5 
Six minutes were required to reach the lowest point and 
during the next five minutes there was a gain of but 05°. 
Stirring was stopped at the end of eleven minutes. 
Lowest attainable temperature.—In addition to Guthrie’s dis- 
coveries already mentioned, he found that when two salts 
were used with ice the minimum temperature was unlike that 
of either alone, each exercising an influence over the other. 
Most of my experiments with the calorimeter were made for 
the purpose of discovering whether or not the lowest attainable 
rature of a given salt when mixed with ice is the same if 
that salt is produced in a freezing-mixture of two salts; also if 
it on independent of the initial temperature and the proportions 
u 
The hydrated sulphate and carbonate of sodium were each 
mixed with various nitrates, whereby nitrate of sodium was 
produced and a sulphate or carbonate, usually an insoluble 
ee ope which I thought could not influence the result. — 
: e lowest attainable temperature of sodium nitrate with ice 
is —17° ©, 
The following results were obtained with metals whose car- 
bonates are without doubt anhydrous, insoluble compounds : 
Initial Lowest 
temp. temp. pie) 
Pb(NO,), with Na,CO,.10H,O 19°C. —-17° 36 
“é 74 <e . 0° fey yd 17° 
Ba(NO,), “6 “ec 21 'g” pee is‘7°* 35° 
“¢ “ 4 ie? ae 17° 16° 
Al,(NO,),. 18H,O “ “ 14° wet Bee 
“ce oc “ —4° os 18° 14 
° 
Cu(NO,),.6H,O « «“ apes pe? eS 
ee “ [74 60 Zo 15°+ 13° 
* An insufficient quantity was taken. + Liquefaction proceeded very slowly. 
