NEW PUBLICATIONS. 279 



the light in the process of blanching. A still stronger argument is 

 to be derived from the fact, that in extreme northern latitudes, during 

 the summer, which is all day, plants grow with great vigor and ra- 

 pidity. How do they contrive to do this without any night to digest 

 their food in ? 



Our author comes, on this same page, to the consideration of am- 

 monia, and its absorption by water, and says, " It is the ammonia 

 in rain water, that imparts to it its peculiar softness in washing the 

 hands or clothes." Then cold water should be softer than hot water ; 

 for ahhough water when cold will absorb a large quantity of am- 

 monia, it will lose it when boiled ; but we have slated above, that the 

 hardness of water is caused by the presence of salts of lime ; when 

 tiiese are absent, as they are in rain water, it will be soft. 



Again, "It is the ammonia that escapes from puirifying substances, 

 that causes their offensive smell. But who does not know the dif- 

 ference between the bracing, agreeable smell of hartshorn^ and the 

 loathsome, sickening odor of a putrifying animal carcase ? Ammonia 

 is produced during the decomposition of animal matter; but this 

 putrid smell arises from the compounds of carbon, phosphorus and 

 sulphur, which are also generated. Again, " It is the ammonia in 

 rain water, which causes it to putrify in some degree." The only 

 three substances there are oxygen, hydrogen and nitrogen ; but no 

 combination of these will give the smell of putrefaction. 



Mr. L. recommends the use of charcoal, and explains its action 

 thus : " It will absorb 90 times its bulk of ammonia, and will give 

 it out slowly to the vital attraction of the roots of plants." What 

 is meant by this '* vital attraction ?" Suppose a piece of charcoal in 

 the ground, saturated with ammonia ; if the root of a plant come in 

 contact with it, how far will this "vital attraction" act ? We do not 

 believe it will act at all beyond the mere point of contact, and that 

 is on the outside where there is no ammonia. How then does the 

 charcoal act, is the question. The answer is, if buried in the ground, 

 it will be of little or no use ; but if applied to the surface, where it is 

 exposed to the air and heat of the sun, but where the roots of plants 

 can not reach it, it will act thus : During dry weather it will absorb 

 ammonia from the atmosphere., which ammonia will be washed out 

 and carried down to the roots of plants by the first rain that falls 

 upon it, for water has a much stronger attraction for it than the 

 charcoal has ; again being dried by the sun, it goes through the 



