162 Review of Essays on Calcareous Manures. 



" For that, there is first made a bed of earth, mould or turf, of a 

 foot, or thereabout, in thickness. The clods are chopped down, 

 and then a layer of unslaked lime is spread over them, at the rate of 

 a hectolitre for twenty cubic feet, or a ton to forty five cubic feet of 

 earth.* Upon this a second layer of earth, of the same thickness 

 as the first, is placed ; on this is laid a second layer of lime ; and 

 the whole covered by a layer of earth. If the earth is moist, and 

 the lime recently burnt, eight or ten days will suffice to slake it 

 completely. Then the heap is cut down and well mixed — and this 

 operation is repeated afterwards before using the manure, which is 

 delayed as long as possible, because the power of the effect on the 

 soil is increased with the age of the compost, and especially if it has 

 been made with earth containing much vegetable mould." — Puvis. 



The quantity used in La Sarthe is not more than twelve bushels 

 to the acre, and is laid upon the land in alternate rows, with barn 

 yard manure. In the opinion of M. Puvis, this method, although the 

 least expensive, is the best, and it may be said to be within the reach 

 of almost every American agriculturist. 



The advantage of the use of lime may be stated in a few words: 

 it is an essential part of the seed of wheat, and that valuable grain 

 will not grow in any soil which does not contain it. It may, there- 

 fore, be reasonably hoped that the culture of this plant may, by the 

 aid of lime, in this comparatively cheap mode, be restored in those 

 districts whence it has long been banished. 



In the United States the use of lime is limited to the districts into 

 which the descendants of the Germans, who settled in Pennsylvania, 

 have introduced the method they brought from their native country. 

 It is usual to apply from thirty to forty bushels per acre, and in some 

 instances one hundred bushels have been used to advantage. The 

 limestone, by the analysis of Dr. Cooper, yielded in some instances 

 as much as 16 per cent, of magnesia. It therefore comes into the 

 class of magnesian limestones, the employment of which requires 

 caution, for this earth absorbs carbonic acid from the atmosphere 

 much more slowly than lime, and so long as it is uncombined may 

 be injurious to plants. 



The high price of grain in Great Britain, during the long wars of 

 the French Revolution, acted as a stimulus upon the use of inferior 



* These two quantities do not correspond, but as we have not the original to 

 refer to, we are compelled to take the translation as we find it. ' ' ^ 



