92 [Senate 



sition of the muriate of lime is produced, and the common salt regen- 

 erated. Commencing then with quicklime and salt, we pass to a so- 

 luble salt of lime and caustic soda, and from that to mild soda, and 

 to carbonate of lime and the original salt. If these various changes 

 take place in the midst of peat or geine, it is evident that the caustic 

 soda acts upon the geine, and also evolves ammonia from that sub- 

 stance; secondly, that the muriate of lime, in its finely soluble state, 

 insinuates itself among the particles of the geine; that the soda is also 

 equally diffused, and that when the soda becomes carbonated, it pro- 

 duces an almost impalpable carbonate of lime throughout the whole 

 mass, which, by its equal diffusion through the soil with the geine, 

 acts upon the silicates, as has been heretofore explained." To pro- 

 duce these effects. Dr. D. directs to take one bushel of saltand two bush- 

 els of lime; to make the salt into strong brine, and with it slack the 

 lime. Mix both well together, and let them remain ten days; then 

 let them be well mixed with three cords of peat, shoveled well over for 

 about six weeks, when it may be used. A quantity of salt sufficient 

 to destroy all vegetation, may be applied to a soil with safety when a 

 few months are to elapse before the crop is to be put on; as the che- 

 mical changes which take place, partially neutralize its effect during 

 this time. A small quantity mixed with the soil in each hill of corn, 

 has been found to protect it from the wire worm and the cut worm; 

 indeed there is no substance that insects of all kinds more dread than 

 salt. It is probable, therefore, that further experiments will show 

 that not the least value of salt is to be found in its preventive pro- 

 perties against these depredators. 



Charcoal is a valuable manure, and applied directly to the soil in 

 a pulverized state, produces excellent effects. It acts by rendering 



the soil more permeable to atmospheric air, by absorbing and 

 Charcoal. ... n ,-i ' f i i ■ ^ ■, 



retammg for the use of plants the ammonia of the at- 

 mosphere, or such as falls in showers; by rendering soils with which 

 it is incorporated warmer; and by furnishing a constant supply of 

 carbonic gas to growing plants. The great productiveness of what 

 are called coal hearths, or those places on which charcoal has been 

 burned, has long been a common remark, but this has been common- 

 ly attributed to the ashes, burned earth, &c. on such spots, rather than 

 the coal. The use of coal alone, however, shows that though these 

 other matters are not without their value, the great additional fertility 

 of these places is mostly owing to the coal. Immense quantities of 



