POUDRETTE. 295 



cape into the second reservoir placed under it. Repeated drainings 

 are effected in this way, and when the second basin is also full, there 

 is a deposition of solid matter as in the first ; the more liquid par- 

 ticles are then let off from the second into the third reservoir, and so 

 on in succession until the last and lowest is attained, from which the 

 liquid used to be turned into a watercourse ; but, of late, these con- 

 taminated liquids have been got rid of by means of what may be 

 called absorbing artesian shafts — deep holes pierced in a dry and 

 porous soil. 



When the deposite in the first reservoir is held to be sufficiently 

 consistent, it is drained by lowering the sluicd more and more ; no 

 fresh matter is added, the new charges being deposited in another 

 system of reservoirs. The deposite once drained is in the pasty 

 condition ; it is then taken out with the spade, and spread upon au 

 earthen floor which slopes off on either side, and the mass is turned 

 from time to time to favor the drying ; this process, in fact, is con- 

 tinued until the material has become pulverulent. It is then stored 

 under sheds, or thrown up into pyramidal heaps, the sides of which 

 are well beaten in order to enable them to throw off the wet. 



Poudrette is of a brown color, and weighs nearly 150 lbs. per 

 sack. Put into a retort, and distilled with a heat of from 424° to 

 930° Fahr., it yields 52.6 of ammoniacal fluid, and 47.3 of dry mat- 

 ter, in which we encounter fixed ammoniacal salts, such as the sul- 

 phates, phosphates, hydrochlorates, &c. M. Jacquemart finds that 

 in 100 parts of poudrette there is 1.26 of ammonia, the greater part 

 in the state of carbonate ; but it contains a quantity of animal matter 

 besides, which, by dry distillation, yields a nearly equal amount of 

 the same substance ; whence it follows that poudrette contains 

 nearly 2^ per cent, of volatile alkali, or 2 of azote. By direct analy- 

 sis, I obtained 1.6 of azote. 



Poudrette is spread upon the land at the time of ploughing, from 

 26 to 34 bushels per acre being allowed. On meadow lands it pro- 

 duces very good effects in the dose of about 25 bushels per acre. 

 The disgusting smell of night-soil is, to a certain extent, an obstacle 

 to its general use. This obstacle, however, is only felt in places 

 where agricultural industry, and the manufactures connected with it, 

 are still in a backward state. One remarkable circumstance is, that 

 the disgust which naturally arises from the manipulation of such ar- 

 ticles, has been more especially got over in countries that are justly 

 celebrated for their extreme attention to cleanliness and the easy 

 position of their inhabitants. I quote Flanders and Alsace in proof 

 of the fact. It has been said, moreover, that certain articles pro- 

 duced in soils manured with human excrement contract a smell and 

 taste which give rather unpleasant information of the nature of the 

 manure that has been employed to favor their growth. In the lim- 

 ited circle of my own experience on this subject, I can say that I 

 have observed nothing which favors such a statement. However 

 this may be, Mr. Salmon has succeeded in disinfecting night-soil 

 completely, by mixing it with a kind of animal charcoal obtained by 

 calcining in close vessels a porous earth impregnated with organic^ 



