COMMUNICATIONS. 99 



ing that it should be burnt, while the majority agree that the 

 natural state is quite as good, provided it be properly crushed 

 or ground. And, since the only effect of burning is to expel 

 the water, which, if the heat employed was not too intense, has 

 nothing to do but return as soon as possible, untd the gypsum 

 be restored to its former condition, we take sides with the ma- 

 jority, deeming the difference, if any, not sufficient to pay for 

 the trouble of burning. 



The best method of applying it to fields of grass, is to sow the 

 powder broadcast, in the portion of 200 to 300 pounds to the 

 acre, while the dew is yet on in the morning. The leaves, so far 

 from being injured, appear to rejoice in it. According to Pro- 

 fessor Korte the stage of progress is an item for consideration in 

 the application of plaster. Thus, it was found that different 

 portions of the same field yielded variously, according to the 

 season when the gypsum was spread upon them. While the 



Undressed . . . - yielded 100 lbs. 



That top-dressed, on the 80th of March, " - 132 " 

 " " " 18th " AprH, " . 140 " 



" " " 27th " " " - 156 " 



If it is desired to enrich the soil for clover, it may, with ad- 

 vantage, be sown at the time of seeding ; but in case the crop is 

 already grown, application may be made at almost any stage, 

 and even with much advantage after the crop has been cut : the 

 aftermath will be improved, and the full effect appear the follow- 

 ing season. 



Oypsuni is obtained natively in France, where it constitutes 

 whole ranges of hills in the vicinity of Paris, (hence the name, 

 Plaster of Paris), and in various parts of the United States. — 

 Indeed, it was but recently that Dr. Shmnard, who accompanied 

 Capt. Marcy in his survey of the head waters of Eed Eiver, dis- 

 covered an immense field, probably the largest in the world, ex- 

 tending from the Wachita mountains to within a short distance 

 of the nearest Mexican province. Moreover, throughout its en- 

 tire extent, the gypsum is of the purest quality, and presents it- 

 self to the surface, so as to be easily worked; in describing 

 which, the Doctor remarks : 



