THE BIOLOGY OF DAILY LIFE. J31 



without chemical process, which would destroy the plant- 

 form. 



Hence most poisonous plants are excluded from 

 being sources of food, but not all. For example, 

 tapioca comes from a highly poisonous plant, but 

 then the poison is very volatile, (chiefly prussic acid), 

 and only needs heat (and no chemicals) to drive it 

 away. 



All chemical processes, including even boiling, or 

 maceration, in hard water, tends to injure food. 



^"o one who has ever tried fairly the use of pure 

 soft water would go back to hard. Vegetables keep 

 their beautiful colours when boiled properly in soft 

 water, and no cook would wish to colour up with salt 

 or soda, who has fairly tried the pure water. By 

 "water" I always, like all chemists, mean H 2 0, not a 

 solution of lime-salts, and other abominations. 



Already a grand step in the right direction has been 

 made by the " Salutaris" Water Company, which sup- 

 plies distilled water, without aeration, at a cheap rate. 

 But every house in our towns ought to have pipes 

 supplying really pure water. And if we remember that 

 by taking off the pressure of the air, water can be 

 made to boil at the freezing-point, there can be no in- 

 superable obstacle in the way of a cheap and abundant 

 supply of evaporated and re-condensed water; once 

 its dietic value is recognized. In the country, when 

 sufficiently far from towns and factories to have pure 

 air, the sky is, in our climate, an all-sufficient source of 

 pure water, if a proper provision were made for its 

 collection and storage, only needing to be boiled. 



But, for fear of seeming to be an advocate of nettles 

 and soft water only, as the Diet of Health, let me 



