370 THE GARDENER. [Aug. 



forcing theory of circulation overboard altogether. I also observe that 

 he maintains that hot ice "is not at air' a curiosity; but in his endea- 

 vour to prove this, he is obliged to depart from the generally accepted 

 meaning of the word " hot," and when he is forced to do so in order 

 to support his argument, it is pretty clear the latter is of an unsound 

 nature. That " ice is not always of the same temperature " is a well- 

 known fact ; but, notwithstanding this truth, ice has no sensible heat, 

 and the latter is the right definition of hot, and therefore hot ice would 

 be a curiosity, whatever " C. M." may think or say to the contrary. 

 That ' ; ice is only a transformation of a body " is also true; but " CM." 

 is slightly mistaken when he says, " if that body is converted into its 

 normal condition, water, it expands by the application of heat, like all 

 other bodies." All other bodies, whatever may be their actual tempera- 

 ture, expand if that temperature is raised, and contract if it is lowered. 

 On the other hand, water must reach a temperature of 39^° before 

 expansion commences, so that, until reaching that temperature, water, 

 like its transformation, ice, is an exception to " C. M.'s " rule that "all 

 bodies expand by heat." That " a certain amount of heat becomes 

 latent when ice is converted into water" is also true; but this fact 

 does not assist " C. M." in proving that one particle of water is capable 

 of transmitting heat to an adjoining particle by conduction; neither 

 does it prove that " ice becomes hot when it is being converted into 

 water;" and, moreover, the latent heat of water is of no use for heating 

 our plant-houses, or anything else. The following experiment will 

 show the amount of sensible heat that becomes latent when ice is 

 converted into water. Take a pound of ice and pound it fine ; put it 

 into a wooden vessel of suitable dimensions; pour on to it a pound of 

 water at a temperature of 172°. The result will be two pounds of 

 water — not at a mean temperature between the ice and the hot water, 

 but at a temperature of 32 3 , thus showing that the ice did not become 

 hot in the process of being converted into water. The ice absorbs the 

 sensible heat, and it disappears somewhere and is lost. 



" C. M." tries to make it appear that I admit that water transmits its 

 heat to water, and all other bodies, in the same degree. What I said 

 on this point was as follows : It is true water parts with heat to all other 

 substances with which it comes in contact that are of a lower tempera- 

 ture than itself, but the degree of rapidity with which it does so is 

 measured by the conducting power of the material acted on. If 

 " C. M." construes this into an admission on my part that his facts are 

 " chiels that winna ding," he is at liberty to do so — at least, so far as I 

 am concerned. I would here, however, point out to "C M." that 

 misquoting his opponents is not the most likely way of convincing 

 them that they are wrong. " C. M." "fails to see the difference between " 

 the first promoters and the cause of circulation, as the latter takes 

 place in the hot- water apparatus. Perhaps I will fail in making the 

 difference plain to him. I will try, howe/er. Heat and expansion 



