501 



A package of mineral pliosphate from near Charleston, South Caro- 

 lina, was sent to the laboratory by the Commissioner of Agriculture. 

 Its composition is — 



Water, (determiuetl stt lOO'^ C.) 4.4750 



Orjraiiic matter 33. 8400 



Insoluble silica 7.h620 



Soluble silica 0. 6(150 



Oxijles of iron and alumina 7. 2702 



Insoliil^lo phosphoric aciil 16. 3485 



Soluble phosphoric acid 1. 3860 



Lime 18.0591 



Magnesia 0.1360 



Potassa 0. 1541 



Si)da 1.328G 



Chh)rine : 0.5960 



Sulphuric acid 6.8712 



99. 9927 



Yalue of city wastes. — The German system of experimental sta- 

 tions is furnishing" scientitic agiicnlture with data which cannot fail to 

 Lave an impoitant bearing on the production of tliat region. Mr. Lep- 

 mann, director of the central station in Bavaria, spealis of the loss of 

 fertilizers in the wastes of the city of Munich, which he estimates as 

 containing a population of 177.000. Tlie amount of avaihible nitrogen 

 annually lost iti the human excrements, fluid and solid, of that city, he 

 places at 1,857,714: i)ounds ; to which he gives a value (reduced to our 

 currency) of $153,467. This gives an aggregate loss of nearly half a 

 million of dollars. While this waste is being suffered the German 

 fields are enriched by an annual importation of l,00l),000 hundredweight 

 of Peruvian guano, at a cost of about three millions of dollars. Munich, 

 however, is but one of a number of German cities whose wastes, if cal- 

 culated at the same ratio, wouhl be eqjual in value to the fertilizers im- 

 ported. Mr. Lepmann proposes that this waste be saved. 



Absorption of ammonia by charcoal,. — Journal of the Chemical 

 Society (London) gives a very interesting series of experiments on the 

 absori)tion of gases by charcoal, as that phenomenon is effected by 

 temperatnie. The experiments \vere conducted and are rei)orted by 

 John Hunter, M. A., and were })erformfd chiefly with gaseous am- 

 monia and cocoa nut charcoal. The principle established by these exper- 

 iments is that the absorbent power of charcoal diminishes from 0° Cto 

 55° by a ratio corresponding to the change of temperature; but above 

 that temperature the ratio constantly decreases as the heat increases. 

 These facts have an important agricultural bearing. Vegetable mold 

 owes its dark color chiefly to the jtresence of carbon, substantially in 

 the condition of charcoal, and on this, to a great dejiree, depends its 

 power to absorb gases. At night, when the temi)erature of thesoil falls 

 to 15 C. (GO F.) the absoiptiun of amnH)nia will be active and a stock 

 will be accumulated in the soil ; but when the temperature rises w ith 

 the sunshine the function of the leaves become active and the supply of 

 food for the roots is diminished. 



The Black Soil of Eussia. — We reproduce the following paper from 

 the researches of L. Grandeau, into the nature of the black soils of Rus- 

 sia. This investigation has an impoitant bearing on American agricul- 

 ture, as we have in the Northwestern States and Territories thousands 

 of acres which agree in chemical composition and in physical properties 

 with these Kussian soils. The chief importance of these researches, 

 however, is found in the light which they throw on the part which oxalic 



