OF WATER FOR ORGANIC MATTER. 59 



and water, or carbonate of ammonia, to restore the lost 

 amount, is advisable. A little distilled water and a few 

 expirations into it throngh a glass tube will be sufficient 

 for most cases ; of course after this the ash must be heated 

 again. 



'^^ Professor Miller advises the addition of 0*3 gramme 

 of carbonate of soda to a litre of water, or 20 to 25 grains 

 to a gallon, making allowances in the weighing. 



" The addition of carbonates is especially useful, so as to 

 form nitrates of alkalies when chlorides of calcium or mag- 

 nesium are in the water. Chloride of calcium is observable 

 in water from the clay slates of the west of Scotland, at 

 least in some places. It is found also in Loch-Katrine 

 water, although I have not seen it mentioned. 



" For some years I was inclined to believe that the bitter 

 taste was owing to these salts, until I found it increased 

 by oxidation. I am not prepared, however, to say that 

 they are incapable of modifying the taste, although they 

 exist in quantities very minute.^^ 



It is needless to remark that I consider Frankland's 

 mode of obtaining carbon and nitrogen far superior to 

 any weighing. 



" Use of Permanganate of Potash, or Chameleon. 



'' It must be remembered that the amount of organic 

 matter obtained in the above way may be equal to several 

 grains in a gallon, and yet be quite innocent; for ex- 

 ample, it may be a little peaty matter. One method of 

 trying the quality is given above ; another, of a very con- 

 venient kind, is by the use of permanganate of potash, or 

 mineral chameleon. It will here be called chameleon, as 

 the former term is very long. It is very highly coloured, 

 and its decomposition is known by the disappearance of 

 the colour. 



^' Chameleon is decomposed by putrid organic matter^ and 



