STATE HORTICULTURAL SOCIETY. 181 



the coil, and, overcoming the resistance offered by the superim- 

 posed body of liquid, wend its way to the surface. 



In a mechanical way evaporation has been established, force 

 has been employed and resistance overcome, but meanwhile other 

 attending chemical agencies have been at work. Temperature 

 had of necessity to be intensified in the bubble and the principle 

 of mechanical equivalents complied with before it could start on 

 the journey upward. 



The necessarily excessive and persistent heat has inverted a 

 sensible quantity of the cane-sugar and has left indelible impres- 

 sions upon every element of the liquid even to branding them 

 with the unmistakable legend "tried as by fire." 



Persistent heat is a powerful agent in chemical phenomena, in 

 fact there are many chemical changes which can not be pro- 

 duced without its sjDecial employment. The heat may be strong 

 and of brief application or it may be mild and applied continu- 

 ously through protracted periods of time, but the results in either 

 case are identical. Given the conditions necessary to produce a 

 certain chemical change and that change will surely and in due 

 time take place. 



The effects upon cane juice of high and persistent heat con- 

 tinued through a short period of time and of a low heat con- 

 tinued through a long i)eriod of time are analogous. In either 

 case or under either condition the heat co-operates with the nor- 

 mal acids and with the acids of lime and sulphur, if used, and 

 converts the cane sugar into grape sugar or glucose, and with 

 due regard for the physical laws involved, either of chemistry 

 or mechanics, the status of the phenomena may De reduced to a 

 statement of equivalents, and the results placed one opposite 

 the other with the sign of equality between them. It is simply 

 a question of cause and effect — given certain causes and the 

 effect due to those causes is sure to follow. 



If in evaporation we employ but a very shallow body of 

 liquid — scarcely enough in quantity to cover the coils — the 

 effects of the heat are at once marvellous and concise. Being 

 instantly expended in converting the volume of water into 

 1,700 volumes of steam, and there being no superimposed body 

 of liquid to obstruct free radiation and quick absorption, the 

 1,700 volumes instantly obey the impulse and law of expansion 

 and recoil, and each bear but a fraction of the original volume 

 of heat, and are consequently rendered powerless for working 

 njury to or breaking down the sugar properties contained. 



