CHEMICAL SCIENCE. 289 



moment, in one hectare of cultivated ground, one of meadow, one of the 

 forest soil, and in one metre of river or spring water. The quantity in the 

 soil was, of course, found to vary extremely with the extremes of wet or 

 dry weather. Garden soil, highly manured every autumn, contained, on 

 the 9th of August, 1856, after fourteen dry and warm days, 316'5 grams of 

 nitre in a cubic litre of soil. On the 29th of the month, after twenty rainy 

 days, the same quantity contained only 13 grams of nitre. The greater part 

 had been dissolved out of the superficial soil. 



Some specimens of forest soil, in a state of nature, furnished no indica- 

 tion of nitrates ; others gave 0'7 and 3'27 grams of nitre to the cubic meter. 



The soil of meadows and pastures afforded from 1 to 11 grams of nitre 

 to the cubic metre. Nineteen specimens of good cultivated land gave, 

 four of them, none; others, from 0'8 to 1'33; the richer ones, from 10*4 to 

 14*4; and one fallow, of exceptional richness, as much as 108 grams of nitre 

 to the cubic metre. To the latter, much calcareous matter had been added. 



The soil of a conservatory, from which the nitrates would not be washed 

 away by rains, contained 89, or 161, and some rather deep soil 185 grams of 

 nitre in the cubic metre. 



The sources of the nitre are not difficult to understand when we reflect 

 that a manured soil, especially a calcareous one, is just in the condition of an 

 artificial nitre-bed. The ultimate result of the decomposition of ordinary 

 manure is a residuum of alkaline and earthy salts, phosphates, and nitrates ; 

 the latter, with the ammonia, furnishing the assimilable nitrogen, all-essen- 

 tial to productive vegetation. In incorporating with the soil undecomposed 

 manure, instead of the ultimate results of the decomposition, less loss is suf- 

 fered from prolonged rains washing out the formed nitrates. 



The soluble matters washed out of the soil are to be sought in the water. 

 River and spring water, therefore, act as manure by the silex and alkali, 

 the organic matter, and the nitrates which they hold. The spring waters 

 poorest in nitre of those examined contained from 0'03 to 0'14 milligrams 

 of nitre to the litre; the richer ones from 11 to 14 grams in the cubic metre. 



As to river water: the Vesle, in Champagne, held 11 grams, the Seine, at 

 Paris, 9 grams the cubic metre. These were the richest. The Seine, at 

 Paris, carries on to the sea, in times of low water, 58,000 kilograms, in 

 times of high water, 194,000 kilograms of nitre, every twenty-four hours. 

 What enormous amounts of nitre must be carried into the sea by the Mis- 

 sissippi, the Amazon, and by every great continental river; and how active, 

 beyond all ordinary conception, must the process of nitrification be over all 

 the land ; and how vast the supply of assimilable nitrogen for the use of the 

 vegetation ! Silliman's Journal. 



ON THE ABSORBENT POWER OF SOILS. 



At a recent meeting of the London Chemical Society, a paper from Liebig 

 was read, on the absorbent powers of soils, in which he maintained that the 

 spongioles of plants, in obtaining their supply of saline matter, did not act 

 by simple absorption, but exerted a real decomposing action upon certain 

 ill-defined compounds which the saline matter formed with the insoluble 

 constituents of the soil. 



ON THE COMPOSITION OF VARIOUS PHOSPHATES OF LIME. 



At a recent meeting of the Boston Society of Natural History, Dr. A. A. 

 Hayes made a communication, reporting progress in experiments elucidating 



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