208 AETIFICIAL MANURE. 



contains more than 20 per cent, of geine. Nos. 11 and 12 

 are of this description. 



258. These varieties comprise probably a fair sample of 

 all the peat and swamp muck and pond mud which occur in 

 the various parts of the country. The results stated (256), 

 are those of the several varieties when dried at a tempera- 

 ture of 240° F. The composition of peat ashes has been 

 alluded to (163). They contain, in fact, all the inorganic 

 principles of plants which are insoluble, with occasional 

 traces of the soluble alkaline sulphates, and of free alkali. 

 Twenty samples of peat, from various localities in Rhode 

 Island, afforded Dr. C. T. Jackson an average of 72 vegeta- 

 ble matter, 24 ashes, in 100 parts, dried at 300° 



Silica formed f of the ashes. The remaining salts were 

 similar to those which have been mentioned. 



259. It is well known that all peat shrinks by drying, and 

 when perfectly dried at 240° F., loses from 73 to 97 per 

 cent, of water. When allowed to drain as dry as it will, it 

 still contains about |- of its weight of water. It shrinks from 

 f to f of its bulk. A cord wet becomes ^ to J of a cord 

 when dry. To compare its value with cow-dung, equal bulks 

 must be taken, and hence, to dry peat a bulk of water must 

 be supposed to be added, in proportion above stated, or still 

 better, because easier done, the pile of dry peat is to be esti- 

 mated by the pit left after digging. It will be found, on the 

 above data, that 100 parts of fresh dug peat, of average qual- 

 ity, contain, — 



Water, 85.00 



Salts of lime, 00.50 



Silicates, 00.50 



Geine, 14.00 



100.00 



