1846.] Spontaneous Clumges of Organized Matter. 213 



and with the elements of water produces a substance partially 

 organized in structure, the starch globule. The transition of the 

 starch globule into lignine or woody fibre is supposed to be ef- 

 fected in virtue of mere chemical affinity; the outer layer of a 

 starch globule, of which we have spoken, increases in density by 

 condensation of the outer layer, and also by the absorption of a 

 portion of the water of the inner coats, a cell is formed. To 

 form a fibre we have only to bring together a continuous row of 

 stai'ch globules vrhich, coalescing in part, form a continuous tube 

 or fibre. The lignine or fibre thus produced is represented by the 

 formula C. 12, H. 8, 0. 8. Starch then, is considered the first 

 product of the assimilation of carbon and water, and is in struc- 

 ture and composition adapted for a change into wood. When, 

 however, starch is formed in seeds, or in other parts of plants, it is 

 readily converted into gum and sugar by contact wath albuminous 

 or fermentative principles; it then loses its organized characters. 



Now, lignine is converted into ulmine in the absence of vitali- 

 ty in the organized tissues, by changes which are opposite to, or 

 contrary to those which have just been described in the conver- 

 sion of starch into woody fibre. Here oxygen is absorbed from 

 the air, and carbon is carried OiF in the form of carbonic acid, 

 and a quantity of its hydrogen as v/ater, and the constitution of 

 lignine is destroyed. 



These changes are analagous to, and perhaps identical with 

 those which convert organized matters into manures, the substances 

 being actually oxygenated; and here too, practice is not at fault; 

 it is \vell known that composts must be turned over, and exposed 

 more or less to the atmosphere; and the experienced farmer knows 

 too, tiiat it is possible to carry these changes too far, for if the 

 matters become too much oxidated they are comparatively spoiled. 

 We see some of the effects in heaps of manure from the horse- 

 stable, which are often burnt. Like the cooking of food, there is 

 a point where the process must stop if the greatest amount of nu- 

 tricious matter is to be obtained, and the great desideratum in 

 husbandry is to know how to promote the process and carry it to 

 the precise point required, and there stop it. This is secured by 



