200 Cr.GANIC MANURES. [VIII. 



Deodorizing Putrid Blatter. — x\mong the various substances 

 proposed to disinfect excrements, and at the same time to 

 fix and retain their valuable constituents, some, as sulphuric 

 and muriatic acids, expel sulphuretted hydrogen, and are there- 

 fore objectionable ; others, as the metallic salts, may them- 

 selves be injurious to plants (see Magnus's experiments). 

 Boussingault proposed chloride of magnesium, which would 

 form the difficultly soluble ammonia-phosphate of magnesia. 

 Calloud proposes the mother- waters of salines, containing 

 salts of lime and magnesia, together with charcoal. While 

 the former would form phosphates of slow solubility, the coal 

 absorbs the noxious gases, and by its porosity also oxidizes 

 sulphuret of ammonium into sulphate of ammonia. 



To deodorize human excrements, the best material is pro- 

 bably the pyrolignate of iron, the free acid of which has been 

 previously neutralized by a base (ashes, lime, &c.). 



To prevent the escape of disagreeable and perhaps noxious 

 gases from decomposing animal matter, and to convert it into 

 good manure, E. Brown recommends (Lond. Journ. Arts, 

 1847) pouring into a privy a dilute solution of sulphate, mu- 

 riate, or pyrolignate of iron, or muriate of manganese (from 

 the manufacture of bleaching-salt), stirring up, then covering 

 it with a good absorbent (75 pts. wood-ash, and 25 pts. saw- 

 dust, bone-powder, &c.), and closing the building for 10 

 minutes. Thus freed from odor, it may be transported to a 

 poudrette building, where it is mixed with 15-20 per cent, of 

 a drying powder, dried, and packed. 



Blood may be rendered inodorous and incapable of putrefac- 

 tion by adding to it a solution of chloride of iron or of 

 manganese, which unites with and coagulates the albuminous 

 matter, and then drying it alone, or mixing with absorbents 

 and drying it. 



5. Ashes of Plants. — It is hoped, and with good reason, 

 that an accurate determination of the ashes of plants and of 

 parts of plants, will assist in determining what special mineral 

 substances are needed by those plants, or their parts, for their 

 more perfect development. Hence these analyses have been 



