324 THE GARDENER. [July 



are then inserted in the bed of the propagating-pit ; the hole is made 

 sufficient to admit of the young roots ; the cutting is put in stalk 

 downward; the whorl is bent upward, forming a cup, which is 

 filled with the sand of the bed, and sufficiently watered to firm the 

 whole together. The proper depth for the cuttings is, centre of whorl 

 half an inch below the surface. The bottom-heat is from 75° to S0 C , 

 always giving a liberal supply of water. 



A few weeks will make them ready for being put into 3-inch pots, 

 and placed in the stove till June. When they are finally shifted into 

 5-inch pots, the ordinary compost of loam, leaf-mould, and sand suits 

 them admirably ; and they can be grown throughout the summer in 

 a gentle hot-bed. The pots are plunged to the rim, allowing the 

 plants plenty of room to spread their whorls; and turning them 

 round every second day induces a symmetrical growth, and prevents 

 the roots getting a firm hold of the bed. 



Cuttings taken in March or April, and grown as recommended, 

 will be ready for table decoration by the end of August. 



TT. L. 



HEATING BY HOT WATEE. 



I. 



Allow me to reply as briefly as I can to Mr Hammond's article in the- 

 ' Gardener ' for May, where he criticises my letter in the preceding number. 



In answer to my question, Why water transmitted its heat to ice ? he says,. 

 "I may remark that hot ice would be a curiosity." If I understand Mr 

 Hammond's definition of hot to mean, to raise the temperature of, I may reply 

 that ice becomes hot when it is being converted into water, which is not at all 

 a " curiosity." I consider extreme cold as the absence of heat; and if the 

 temperature of a body i3 raised by the application of heat, that body becomes 

 hot according to his definition, although the general acceptation of the word 

 means sensible heat. He thinks it is impossible to heat ice by any means. 

 Bat I have to inform him that ice is not always at the same temperature. 

 " Ice," he says, " is an exception to the rule that all bodies expand by heat." 

 But I must remind him that ice is only a transformation of a body, and if that 

 body is converted to its normal condition, water, it expands by the application 

 oi heat, like all other bodies. His test of the conducting power of water is to 

 drop a ball of ice into hot water for a few minutes, then take it out, and put 

 what remains unthawed amongst cold water, and because the ice does not raise 

 the temperature of the water (which must, according to the law of nature, 

 already be at a higher temperature than the water), but has " an opposite effect," 

 he "thus proves that the particles of water are incapable of transmitting 

 heat to each other by conduction." But from their "having the opposite 

 effect" we may infer they are capable of conducting cold — or in other words, 

 that it has lowered the temperature of the water, which proves most effectually 

 that the heat has been absorbed by the ice. I will also here inform Mr Ham- 



