184 [Assembly 



ferent pressures, and in steam generated at the temperature of 

 212°, and heated afterwards out of contact with water. In the 

 first of the two cases, he reaches the conclusion that " natural 

 steanij however varying in density or temperature^ is one invariahle 

 atomic coinpound of water and caloric, and as definite as any chemical 

 atomic compound whatsoever^ This, when translated into more 

 familiar language, is no more than the well-known law which 

 has long been received as approximately, but not exactly true, 

 viz, that the Slim of the latent and sensible heat in the vapor of water ^ 

 whatever he its temperature or density, is a cojistant quantity. Mr. 

 Frost's experiments do not appear to furnish better grounds for 

 considering this law as more than approximately true, than those 

 of others ; and to receive it as more than an approximation, is at- 

 tended with difficuities which have so often been pointed out, 

 that it is unnecessary to state them in this report. Upon this 

 law, however, Mr. Frost founds an argument against the profita- 

 ble application of high steam, on which head it is sufficient to 

 state that on this very law is founded tlie reason why liigh 

 steam can be employed with advantage ; because the tension due 

 to its increased temperature is obtained without cost. In respect 

 to steam generated at 212°, and subsequently heated out of con- 

 tact with water, Mr. Frost infers that the increased tension which 

 has been exhibited in the tables above set forth, is obtained by 

 the addition of comparatively small quantities of heat. Thus to 

 raise the dry steam from a temperature of 212° to 650° and give 

 it a tension of 9.8 atmospheres, requires no more heat than is to 

 that which is required to raise water from a temperature of 50° 

 and convert it into steam of the tension of one atmosphere, as 

 38 : 32. Upon this Mr. Frost founds a theory, that steam heated 

 out of contact with water, becomes a new atomic combination 

 " of water and caloric." We do not see that it is necessary to 

 resort to this hypothetical mode of expression, nor is there any 

 experimental evidence of a change in the relations of the aqueous 

 matter to latent heat. All that occurs can be explained in lan- 

 guage more familiar, and which, although also hypothetic, is so 

 universally received that it may be used wdth as little risk of be- 

 ing misunderstood, as if it truly expressed facts. In this lan- 

 guage the amount of the discovery of Mr. Frost may be stated, by 

 saying that steam heated out of contact with water has a very 



