COAL-ASHES. 315 



comoination with lime, this peat could only ha^e contained 4.1 per 

 cent, of gypsum. 



These analyses will show that-the composition of peat, or turf, is 

 very various. The varying and dissimilar effects produced by turf- 

 ishes, may probably be owing to this variety of composition. Turf- 

 ashes, in a general way, may be used as a substitute for gypsum ; 

 but this is upon the presumption that they contain lime, either in the 

 state of carbonate or of sulphate. The Vassy turf-ashes, for ex- 

 ample, may be employed for gypsing meadows, inasmuch as they 

 contain a quarter of their weight of sulphate of lime. 



The ashes from pyritic turf ought not to be used without great 

 circumspection ; they usually contain a quantity of iron pyrites 

 which has not been destroyed in the burning, and which, exposed 

 to the action of the air, gives rise to the formation of green vitriol, 

 or sulphate of iron, which may prove prejudicial to vegetation. 

 These ashes are generally of a red color, and very heavy, in con- 

 sequence of containing a quantity of the oxide of iron. Good turf- 

 ashes ought to be white and light ; the sack ought to weigh some- 

 thing less than a hundred-weight. Schwertz recommends us to keep 

 them from the wet ; but at Bechelbronn, where we use large quanti- 

 ties of peat-ashes, we find no ill effects from leaving them exposed 

 to the rain ; frequently, indeed, we moisten them with water from the 

 dunghill, in order to add to their properties as a mineral manure, those 

 that belong to organic manures. On the whole, however, it is cer- 

 tainly better, for many reasons, to keep them dry ; they are more 

 easily carried, and they are more easily spread. 



Turf-ashes of a good quality, that is to say, which include in theii 

 composition a large proportion of calcareous and alkaline salts, are 

 adapted to crops of every description ; but it is upon clover especially 

 that their influence is truly surprising. This fact is well established 

 in Flanders ; but one must have employed them one's self to have any 

 adequate idea of the improvement they produce. There is no risk 

 of giving too large a quantity. In winter, when we have peat-ashes 

 at our disposal, we give as many as 60 bushels per acre to our clo- 

 vers ; we scatter them even upon the surface of the snow, and dis- 

 tribute them by means of the rake in the spring. The Dutch use 

 these ashes in still larger quantity, applying, at two different times, 

 from 100 to 160 bushels per acre to their clover fields. Accord- 

 ing to Sinclair, the Dutch also make use of an ash procured from 

 a turf which during winter is in contact with brackish water, a cir- 

 cumstance which renders this ash particularly rich in alkaline salts. 

 It is sowed by hand, in the spring, upon clover, and the following 

 year an abundant crop of wheat is obtained. The same material is 

 also used in the cultivation of the hop ; and it is said that, administer- 

 ed in small quantity to the roots of the vine, they preserve the plant 

 from the attacks of destructive insects. 



Coal-ashes. Coal, like the two last combustible materials, is the 

 product of vegetables, which, however, have undergone such a 

 change as to have lost almost every trace of organization. Coal of 

 different kinds contains from 1.4 to about 2.3 per cent, of ashes, and 



