No. 129. J 209 



sufficiently fine, it begins to develope itself as carbon in a new 

 series of actions, it absorbs and retains the ammoniacal and other 

 gases, resident in the atmosphere in contact with it, and brought 

 down by the showers holding them in solution, once in the soil 

 they are retained by the carbon, with a power which yields 

 in intensity, only to the energy of a growing plant, at the same time 

 by the combined action of heat, air and moisture, a portion of it 

 receives oxygen from the atmosphere and becomes carbonic acid, 

 which is condensed and absorbed by the remaining carbon, un- 

 til required by the plants growing upon it The extent and ra- 

 pidity with which these actions take place is only directed by 

 the degree of fineness to which the carbon is reduced, and its 

 action as an active manure is also in the same proportion. 



The more perfect the mechanical division, the more rapid and 

 energetic will be its chemical action. A further advantage ari- 

 sing from the presence of carbon in any form in the soil, is its 

 property of absorbing both heat and light, rendering the soil 

 warmer and more stimulating to the growing powers of plants. 

 Heat and light are both powerful incentives to chemical action 

 as the whole history of chemical science will teach, and it is 

 most of all evident in the chemistry of organized bodies ; the 

 influence of heat and light seems to be essential to the life and 

 proper growth of plants ; nor are their effects merely confined to 

 those portions of the plant above the surface of the soil ; it is highly 

 probable that their action upon those parts beneath the surface 

 may be quite as important. The lives of plants are but a series 

 of the most complicated and interesting chemical actions, all of 

 which are more or less powerfully controlled by these two agents, 

 light and heat, hence the value of any substance calculated to 

 enable the soil to retain these highly important stimulants. 

 All practical men know the value of a warm soil, and to such 

 the value of a means of correcting the opposite property will be 

 at once apparent ; plumbago of all other means, seems from its 

 powerfully blackening properties best calculated to produce this 

 so highly desirable result ; a very small proportion is sufficient 

 to perceptibly darken the color of the soil, and in a correspond- 

 ing degree to increase its power of absorbing light and heat. 



[Assembly, No. 129.] 14 



