AMERICAN INSTITUTE. 367 



been found in small proportion in wheat and in the potato, but in red clo- 

 ver it is the only constituent that is not destroyed by fire. No other 

 earthy matter has ever been found in the ashes of red clover, and hence, as 

 far as that plant is concerned, sulphate of lime cannot be replaced by any 

 other substance. Red clover appears to derive none of its food from the 

 constituents of the soil, except at the very act of ripening it's seeds, and 

 thus the application of plaster to a soil in wbich nothing else would grow, 

 has, in well known instances, produced a luxuriant growth of red clover. 

 The President had himself, when a director of the Moha\\k and Hudson 

 (now the eastern portion of the Central) railroad, advised that the slopes 

 of the deep cuts, and the sides of the embankments, constructed of a flow- 

 ing sand, be sown with a red clover seed and plaster, to prevent their de- 

 struction by the wind. The experiment was successful in the production 

 of a luxuriant growth of the plant, but was more beneficial than could have 

 been anticipated, for under the shelter of the red clover the white clover 

 and the seeds of true grasses took root ; and these slopes are in the present 

 day, after a lapse of mote than thirty years, covered with a green sward, 

 in which the red clover is seen, if it be seen at all. 



It may be laid down as a rule that, in all but a few excepted positions, 

 if even a straggling growth of summer grain can be obtained, the application 

 of plaster will cause a tolerable growth of clover, and that this, if returned 

 to the soil while in a succulent state, may furnish the material of a more 

 plentiful harvest. But the clover must be returned to the soil, or employed 

 in feeding cattle whose manure is made use of on the farm, otherwise the 

 stimulus of plaster upon one particular grovvth may render the ground so 

 barren that it cannot be restored except at great cost. The exceptions to 

 the use of plaster are found in soils which already contain sulphate of lime, 

 and in those in which free oxalic acid exists. The former can never be 

 benefited by plaster ; the latter may be prepared for its beneficial use by 

 the application of lime. The President then referred to the very interest- 

 ing account which had been given, by a gentleman who preceded him, of 

 his successful treatment of a sour and mossy soil, by slaked lime and 

 plaster. This instance he characterized as a most successful application of 

 a chemical principle under the direction of practical intelligence. 



Another exception, he stated, was usually made to the beneficial use of 

 plaster, namely, to the prevalence of sea air. He did not, however, think 

 that the action of the air of the sea could possibly produce such an effect, 

 and was inclined to ascribe it to the other causes already assigned. Pie 

 had seen plaster used to advantage upon clover on ground almost surrounded 

 by the tide ; and in villas around New York, plaster had improved grass 

 plats. The instance to which he referred was on the Kingsbridge farm, 

 once held by Ptobert Macomb. The substratum was white marble, and the 

 soil abounded in carbonate of lime. On this farm large crops of clover 

 were obtained i y the use of plaster, while on the ridges to the east and 

 west of the marble formation, the subsoil of which rested on gneiss and 

 moca slate, no beneficial effect followed the application of gypsum. Chem- 



