377 



bases, groups them as they would separate when evaporated, 

 will report, as in my first example. 



But there are strong grounds for believing that under the 

 influence of the water present in very weak solutions, like 

 natural waters, the grouping is the direct reverse of that 

 which takes place when that influence is withdrawn by evapo- 

 ration. I need not here detail these reasons which are in 

 part drawn from considerations of the medicinal efi'ects of 

 stronger mineral waters : sufficient to observe that there is 

 nothing d priori illogical in the view that where water is 

 the agent in imparting fluidity, the state in which the salts 

 subsist, while thus fluid, should be that of those most soluble; 

 that is, having most disposition to assume this kind of fluidity, 

 and these also possessing the greatest affinity for water, so 

 far as solubility in a fluid denotes affinity for it. 



The chemist who, whatever his reasons for adopting the 

 hypothesis of salts of greatest solubility," has adopted 

 and adheres to it, will state his analysis in the second form — 

 carbonate of soda, sulphate of lime, or, in the further instance, 

 carbonate of soda, sulphate of lime, carbonate of lime. I 

 belong to the " greatest solubility" faction, as believing it, 

 though not perhaps invariably applicable, to express generally 

 what actually takes place in nature, and in the numerous 

 analyses in which I am engaged of waters for medicinal 

 purposes, to be also the most useful practically. But in 

 analyses of railway waters, or waters for boilers of any 

 kind, where we have to do with the results of evaporation, 

 and with these only, I consider it my place to say what 

 evaporation will produce, rather than to mislead by attempts 

 at theoretical exactitude. If I speak in one language to 

 physicians, and in another to engineers, each is, however, 

 a faithful expression of, and exactly equivalent to the other. 



One circumstance which I believe often strikes those to 

 whom the subject is new, is the smallness of the quantities 



