Friction or Compression, 57 
that of the fly-press: we subjected it to a new shock ; and 
performed a third operation with the same precautions, 
In order that we might not be deceived as to the tempe- 
rature acquired, we submitted to the thermometer a piece 
of metal similar to that which we had left some time under 
the fly-press, in order to ascertain the temperature of it 
precisely, and we noted the heat which the piece yielded 
that had been struck. ‘ 
Experiment made with two Pieces of Copper. 
Increase of Temperature expressed in De- 
grees of the Centigrade Thermometer, 
Degrees. 
; First piec€ sseececessacesenes 9,69 
First shock ante PIECE ..eeeeesececeves 11,56 
First piece .ccsepeewence stun 4306 
Second shock } ooo PROGR vaig steiner ie biaryle ia 2,5 
, First piece ....cesseeessceeee 1,06 
Third shock able PIECE sce is ooo Jeena > PANGS 
The total quantity of heatextricated from the two. pre- 
pared pieces is nearly equal; for, on adding the numbers, 
we find 
For the first piece ,.,.cccpscessepeserenpe 14,82 
For the second piece ....,e0c-seresse++s-0 14 87 
Experiment made with two Pieces of Silver. 
Increase of Temperature expressed in De- 
grees of the Centigrade Thermometer. 
Degrees. 
; WISE DICCE ia ata nia pitietn fe sivinie wiareaet 
First shock BECOME WICLE vis io un: sjaie, a.nh9i0)h sain rego 
FEVWAE DEO. o. ssa. lguals-cvete nis San nase 
Second shock | 0 yc8 TUBCE in inveiin ina se efoto liad 
: PURBE PICCE oy 5 ini bin gine apnea sina eae 
pee snack. ge PIECE os pececesgcseren, 1,12, 
Total for the first pieces... 8,19 
for the second piece.. 6,37 
Several other experiments gave analogous results. 
But after three shocks of the fly-press, ‘he pieces when 
struck again, either did not acquire a sensible heat, or ex- 
hibited it in a lower degree than in the third shock. 
Gold afforded a heat stil] inferior to that of silver. 
We afterwards proceeded \o ascertain the relation which 
exists between the foregoing effects and the condensation 
of the volume of each metal. We took the specific gra- 
yity of the piece of gold at 6° of the centigrade thermo-~ 
j meter. 
*% 
