ON THE USE OF GYPSUM. 291 



rankness of the previous clover. Its efiect upon 

 turnips is doubtful ; and some will not allow that it 

 is beneficial to potatoes. Davy lays it down as a 

 fact, that it is most beneficial to those plants which 

 always afford it on analysis ; and the small grains 

 are not found to contain it at all. Many instances 

 are given where its application has doubled and 

 tripled the clover-crop. 



The quantity which should be applied to the.Mcre is a 

 point quite unsettled ; and it should probably be va- 

 ried according to soil and circumstances. John. 

 Taylor, of Virginia, and Judge Peters, of Pennsylva- 

 nia, concurred in opinion, that on lands where it was 

 applied annually, one bushel to an acre was an ample 

 dressing. In Europe it is recommended to dress 

 with five or six bushels to the acre. We have gen- 

 erally sown but a bushel ; but last spring, by way of 

 experiment, we doubled the dressing on a portion of 

 a meadow, and found the grass there much the heav- 

 iest. It is advisable to try it in different quantities, 

 and to note the result of each, as a guide to future 

 practice. 



The time of applying gypsum is generally in the 

 spring, sometimes as late as May or June. The 

 writer of British Husbandry recommends, with much 

 plausibility, that gypsum be applied to clovers semi- 

 annually, viz., soon after the crop is mown in sum- 

 mer, and in the spring just after the plants have be- 

 gun to shoot. We shall be thankful for memoranda 

 of any experiments that may have been made in this 

 practice in our own country, and also whether it 

 produces a better effect when laid on in dry than in wet 

 weather. The work from which we have just quo- 

 ted dwells with emphasis on the importance of hav- 

 ing the gypsum attach to and remain upon the leaves 

 of the young plants, and repeats the charge to sow 

 it when the leaves are wet with dew or with a re- 

 cent light rain, and never just preceding or during a 

 rain. Professor Low says that mineral substances, 



