218 Dr. John Gorrie on the 
condensation) is, nearly, as 1 to 21; and, therefore, the relation 
of the heat retained by the air, after ‘admixture with the water of 
injection, is equal to about one twenty-first part of the 8° F., 
which the water of injection absorbs, or is about the ,% of a 
degree of Fahrenheit at the specific heat of water. 
2. Another correction of the table is necessary on account of 
the heat of condensation, which the water of injection is unable 
to absorb, imparting an increased elasticity to the air in the reser- 
voir... This air being confined within fixed bounds, the effect of 
the heat is to increase its pressure on the surface by which it is 
e7, confined, instead of the natural one of enlarging its dimensions. 
wale The consequence is that the gauge of the reservoir marks a 
higher tension than it would have if all the free heat of the air 
7 were absorbed. The actual changes of elasticity which are pro- 
duced by. mechanical condensation, without allowing the com- 
pressed air'to lose any heat after compression, and for. all propor- 
. ae} tions inawhich that heat is retained, have been mathematically in- 
Se. - Present attained, to find a place in this communication. Posses- 
_ "sing a more important bearing upon the quantity of cooling effect 
rd “reduced by the expansion of condensed air, and still more ina 
3 _ relation with the quantity of mechanical power consumed in the 
—n condensation of air, they will be examined more minutely when 
s+ .  Lcome to consider these portions of my subject. At present I 
eh deem it sufficient,to say that, from the partial calculation I have 
: pee “male, T feel authorized to:consider. that 8° F. of unabsorbed heat 
| yi * "add to the ie a a - re under a tension of six atmospheres, 
ere 9 ressure 
na 
Poe the, Afeenee between the temperature 
wd tha Fea girrounding medium. . As this 
us,.is. but’8° F., the rate” “at which 
Pie sonnel newest by 
e charedier im iat ‘bermade for the 
of the piston-and ‘plston rod of the 
a .the’ ‘eburse is and other ex- 
Cc 
bu th hoy. ee 
faly es, of the® 
