POTASH— SOAPBOILERS' KEF USE. 



contains themselves act as valuable manures, as soon as their intensity 

 is destroyed by diffusion through masses of earth. Such at least 

 appears to be the general opinion of practical gardeners. 



Potash. — The ash which is left after wood or other vegetahle 

 matter is burnt, consists to a great extent of Potash, an alkali 

 which seems to be indispensable to healthy vegetation. In 

 uncleared countries the trees are burnt for the sake of this 

 substance, which, after proper treatment, becomes the pearlash 

 of the shops. It occurs in all plants, and with Soda and Lime 

 is regarded by Liebig as specially destined to serve as a base 

 for the organic acids of vegetation. In its caustic state it actd 

 on decaying matter like Lime ; as a manure it is only known 

 in the form of some salt, of which the carbonate, chloride, and 

 nitrate alone deserve mention. The carbonate is the common 

 form in which it appears in wood-ashes. The periodical 

 burnings of whole districts of heather, or bushes, or grass 

 land, so common among savage. nations, is for the purpose of 

 manuring land with carbonate of potash, after which the 

 scorched land is rapidly covered with a briUiant coat of green. 

 The chloride exists in soapboilers' refuse, a good manure, whose 

 efficacy is chiefly owing to this salt. Nitrate of potash (or 

 Saltpetre) has a great influence on vegetation, promoting vigour, 

 and rendering the tissues solid. It probably owes its action in 

 part to the nitrogen it contains, and in part to the potash. 



( According to Persoz, potash contributes directly to the formation of 



^ flowers and,_fridt, and therefore he recommends it to be applied to 

 the Vine in the following manner : " When it is wished that wood 

 should be developed, the Vines must be placed in. a trench and covered 

 with 3 or 4 inches of earth, with which have been mixed, for every 

 square yard of the surface of the trench, 8 lbs. of pulverised bone, 

 4 lbs. of pieces of skin, leather, horns, tanners' refuse, &o., and 1^ lb. 

 of gypsum. (Here ammonia is depended upon. ) 



" When the wood is sufficiently formed, which will be in a year or 

 two, aooordiag to ciroumstanoes, the roots must be supplied with salts 

 r of potash, in order that the fruit may be produced. For this purpose 

 it is necessary to spread over the trench, at a distance of 3 or 4 inches 

 from the buried wood, for every square yard of surface, 5| lbs. of a 

 mixture formed of 8 lbs. of silicate of potash, and 2f lbs. of double 

 phosphate of potash and lime. The trench is then to be filled up, and 

 the roots have as much potash as they will want for a long time. To 



