WITII REFERENCE TO HORTICULTURE. 65 



solubility of organic matter already in the soil ; and in performing this office, 

 it is found to be more efficient than potass. 



209. Soot is composed of the various volatile matters derived from the 

 burning of coal or wood, together with carbon, and earths which have been 

 mechanically carried up the chimney with water in the form of smoke. 

 From experiment it appears that soot owes its value as a manure to the 

 saline substances which it contains ; and these are chiefly the carbonate and 

 sulphate of ammonia, together with a small quantity of a bituminous sub- 

 stance. The fact of carbonate of soda proving useful as a manure is un- 

 doubted, though it is difficult to explain in what manner it acts, unless, like 

 saltpetre, it stimulates the roots. Soot when applied in gardens is generally 

 strewed on the surface, and it is considered as annoying snails, slugs, and 

 worms; though by no means killing them, as is frequently supposed. Its 

 effects are rarely perceptible after the crop to which it is applied ; and there- 

 fore, like liquid manures, soot affords a quick return for the capital em- 

 ployed in it. 



210. Street manure, or that which is swept up in the streets of towns, 

 consists of a great variety of matters, animal, vegetable, and mineral. Jn 

 the manner towns are now kept, it is small in quantity and of little value ; 

 but formerly it was among the richest of all manures. When collected in 

 quantities, even though containing a large proportion cf earth and coal ashes, 

 it ferments powerfully, and will continue giving out heat throughout a 

 whole summer. For this purpose it has been used in forcing- gardens as a 

 substitute for tanners' bark and stable-dung ; and it has the advantage of 

 not subsiding so much as those materials. Wherever it can be obtained, it 

 may be applied to all soils ; and when obtained from towns still under the 

 old system, it may rank next to nightsoil and bones. 



211. Composts of vegetable or vegeto-animal matter and earth are of various 

 kinds. The most common in gardens is that produced by rotten leaves or 

 vegetable refuse mixed with sand or with some other earth, or with stable- 

 dung : composts of bones are likewise formed in this manner, and also of peat, 

 where that material abounds. Peat composts have been already mentioned. 



212. Mixed manure in a liquid state consists of the urine of animals, 

 soap-suds, the foul water of kitchens and other offices, waste surface or rain 

 water, and drainings of dunghills. The most advantageous way of employing 

 it is by applying it, after being properly diluted and fermented (182), di- 

 rectly to growing crops. It may also be profitably employed by throwing 

 it on heaps of vegetable matter, such as moss, leaves, straw, or any vege- 

 table refuse matter whatever not containing woody matter of several years' 

 growth. In this way, Jauffret, a French agriculturist, proposed to create 

 immense quantities of manure by fermenting weeds and other refuse 

 collected by hedge-sides, or on commons or wastes. The fermentation 

 of such matters does not take place without the aid of animal manure 

 or stable-dung ; but, when once commenced, it can be continued for aii 

 indefinite period by adding to the heap. If the liquid manure and the 

 excrementitious matter accumulated in every large establishment, independ- 

 ently altogether of the stable manure, were collected and fermented, we have 

 little doubt it would suffice for all the kitchen-garden crops ; the refuse of 

 these crops and the weeds of the garden being added and fermented. It is 

 highly probable that every individual animal produces as much manure as 

 would raise the vegetables necessary for his support, because in the nourish- 



