161 MANURE. 



about 5 cwt. of farm-yard dung. But no comparison between 

 the two can safely be made. The one runs its course rapidly, 

 the other acts slowly. The one exerts all its influence in a 

 season, the other reserves its fire, and acts for two or more 

 seasons. 



When it is determined what portion of farm-dung acts in 

 a year, then may that fraction be compared with gadou. If 

 the fraction is ^, then 50 of farm-yard dung are equal to 100 

 Flemish manure. The proportion of azote in the last being 

 0.22 per cent , the real relation becomes to ordinary yard- 

 manure which contains 0.41 per cent,, as 182 : 100. Hence, 

 it is on certain crops only, that this and similar rapidly de- 

 composing manure should be applied. For lightening, 

 breaking up, and loosening the soil, ameliorating its condi- 

 tion, farm dung is better than gadou ; and even where that 

 is fully applied, an occasional dressing with yard-manure is 

 considered essential. 



Each substance used for a manure cannot be considered in 

 detail. The composition only, will be mentioned. Among 

 the mixed manures, poudrette and guano rank next to 

 gadou. Poudrette is night-soil partly dried in pans, and 

 mixed up with variable quantities of charred earth, peat 

 charcoal, or ground peat and plaster. Its value will depend 

 on the circumstance, whether its ammonia and salts are 

 saved, or lost, in the manufacture. If sulphate or muriate 

 of lime is added before drying, then the volatile carbonate 

 of ammonia will be changed into sulphate of ammonia, and 

 sal-ammoniac. Thus, not only the most valuable portion of 

 night-soil will be retained, but the salts of lime will be much 

 increased. The peat not only retains a portion of gaseous 

 ammonia, but its geine by this act is rendered more soluble. 

 All night-soil from vaults has begun to evolve ammonia, 

 hence the advantage of mixing ground peat or piaster with 



