by the mutual reaction of Solid Substances. 213 
With the nitrates of zinc, manganese, iron and chromium the 
results were not so free from modifying influences as I had 
anticipated, basic aeaeebiss being formed not wholly insoluble 
at low temperatur 
The interesting ‘fact was thus revealed that ferric carbonate 
or basic carbonate exists in the liquid form at a low temper- 
ature, say—20° C. The color is a deep red, and as the mixture 
gradually warms CO, is rapidly given off, causing the contents 
of the beaker, which was not at first more than half filled, to 
overflow and insoluble Fe,O, to be deposite 
= itial Lowest 
temp. temp. Loss. 
Mn(NO,),. 6H,O with Na,CO,.10H,O 18° -14° 32° 
“ “ “6 AE bg — 26° 24° 
%Zn(NO,),.6H,O  “ Mi 20°) = OIE 8B” 
“ “ Pog —21°5° 205° 
Cr'(NO,),. 18H,O “ “ me Bo. ee GO Ae 
Fe(NO de 18H,O “ i 186°, IZ. Bie? 
74 ce 10°5° ne 17° 27°5° 
ce <4 (<4 ak a ais 94° 21° 
It will be seen from these and the following results that the 
minimum temperature is not independent of the initial temper- 
ature; it was also found that the lowest point varies with the 
proportions taken : 
a 2 temperature. Lowest 
2nd. temp. 
Pb(NO,), with Na,CO,. 10H,O 45° a2", 195° 
Fe,(NO,),. Ho . 39° 32° — 4° 
Al,(NO,),. 180 “ is BT ok BR ey ee RP 
With the nitrates of magnesium and calcium the tendency 
to metathesis is so slight that the Hitec de is not rapid 
enough to produce any great degree o cold, and with an ini- 
tial temperature of —2° there is no liquefaction whatev 
The time allotted for the completion of my graduation the- 
sis, of which this paper gives the substance, rendered it neces- 
some years, but whom the pressure of other duties has prevail 
from pursuing an investigation. He has, however, given con- 
siderable thought to the matter, one of the results of which is 
his theory of the “diffusion of solids.” His s predictions that 
there may be liquefaction without chemical reaction, and that 
the product obtained from the mixture of salts is sometimes 
ydrated, were both confirmed by the results of my work. He 
devised the calorimeter which was used, and I am indebted to 
him also for valuable suggestions and advice. 
Mass. Inst. seman June 3, 1881, 
* The tempera of Na,JO; . 10H.O could not be raised so high as that of the 
other ‘abe atte t melti ing. 
