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are present in the same cold solution, the ammonia takes 

 the muriatic acid, and remains with it in solution, while 

 the lime combines with carbonic acid, and precipitates as 

 carbonate of lime S ; yet at the temperature of boiling- 

 water, these affinities are reversed. Lime then takes muria- 

 tic acid, or, in modern nomenclature, the calcium of lime 

 takes the chlorine of muriatic acid, and chloride of lime, 

 an extremely soluble salt, remains in solution; while am- 

 monia takes carbonic acid, and is driven off as carbonate 

 of ammonia. Thus all precipitation of carbonate of lime 

 is prevented. Dr. Ritterbandt assumes that sulphate of 

 lime, and carbonate of magnesia, the other and minor 

 constituents of some crusts, will not form hard or coherent 

 masses without the presence of carbonate of lime ; and 

 without being prepared to confirm this assertion, I should 

 readily admit that if we get rid, by this, or any other 

 method, of carbonate of lime, the others are, from their 

 very quantity, of less importance. 



Mr. Gooch, the engineer to the London and South 

 Western Railway Company, states that he has tried the 

 method to some extent in locomotive engines with great 

 success. He likewise states that it has succeeded in pre- 

 venting incrustation in marine boilers, fed by salt water, 

 and that it is only necessary to draw off the residual 

 concentrated solution of salt once in ten or twelve days, 

 instead of daily. Mr. Gooch states that he has had the 

 water, after the use of muriate of ammonia, tested by a 

 chemist, and that it shows no sign of the presence of any 

 metals which would indicate the action of muriate or carbo- 

 nate of ammonia, either on the iron boiler or the brass or 

 copper tubes. It would be desirable that this should be 

 further tried, and confirmed. Another of Mr. Gooch's 

 statements is, I doubt not, correct : that when an incrus- 

 tation has been formed, it is detached, and partially or 



