I. AGRICULTURE AND RURAL ECONOMY. 409 



30 per cent, of cartilage, and 60 per cent, of earthy salts, the lat- 

 ter containing, for the most part, the phosphate of lime, Avith 

 some carbonate and common salt. It was only after some 

 time, and by direct experiments with bones freed from fat, 

 that it became an accepted fact that the fat played no fertil- 

 izing part, but rather the opposite, and experiments were in- 

 stituted in the direction of more complete pulverization. 

 First, bone-ashes were prepared; then, in 1850, the- bones 

 Avere steamed and then powdered, and afterward fermented 

 bone-flour was produced. 32 (7, April 26, 18V3, 215. 



FAILURE OF THE SYSTEM OF SEWAGE lERIGATIOX. 



M. Lefeldt was commissioned, by the Minister of Agricult- 

 ure of Prussia, to visit England for the purpose of determin- 

 ing the value of the different systems of utilizing sewage; 

 and he has lately published a report on the subject, which is 

 not encouraging in regard to the employment of these sub- 

 stances as manure. His principal inquiries were with ref- 

 erence to the method of sewage irrigation. He shows that 

 this, instead of being a matter of profit, is actually the cause 

 of considerable loss ; and he quotes the statements of experts 

 to the effect that not a single sewage farm in England is 

 worked to advantage, notwithstanding all calculations as to 

 apparent gain ; and maintains that it is utterly irrational to 

 expect any thing but loss, even though the sewage itself 

 may possess considerable manurial value. 



In examining into the Edinburgh irrigation meadows, M. 

 Lefeldt ascertained that, if the selvage water is allowed to 

 flow upon the land until two days before mowing, the growth 

 is found to be most luxuriant, with the single drawback that 

 cattle refuse to eat the grass. The capillary tubes for some 

 inches above the roots are found to be filled with nnassim- 

 ilated foecal matter. It was also ascertained that at a con- 

 siderable distance from sewage farms, when the w^ind was in 

 the proper direction, the emanations were extremely offen- 

 sive, requiring a long experience to become accustomed to 

 them. In certain localities, where the sewage is disinfected 

 with carbolic acid previous to irrigation, there was less com- 

 plaint of offensive eflluvia, and this is consequently suggested 

 as a suitable preliminary treatment. According to the cal- 

 culations of M. Lefeldt, an acre of land should not receive the 



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