IPARMERS' REGISTER— GYPSUM. 



nit 



a shovel li-oiu a wagon, having it moving about 

 •he field. This is a method 1 have ne\'er seen 

 practised, and probably nevei- Fhall. 



"The course of" culture, or series of crops raised 

 on lands to whicli it is apphed for a number of 

 years. " Plaster is used in connection with clover 

 to a great extent, by our farmers. Clover seed is 

 pown on wheat in Marcli, then ])laster. The clo- 

 ver seldom lails, the plaster protects the young 

 plant during the early droughts. The next year 

 early in June, tlie clover is turned under; there it 

 remains until after harv'est: the land is then plough- 

 ed and sown to wheat; the next spring clover seed 

 and plaster is sown again. The clover is made 



This is denominated the water of crj'staliza- 

 tion, which is one of the component parts of all < 

 crjstalized substances. Now what would be 

 the eflcct of heat upon tliis compound, or what 

 change Avould it jn-oduce? 



If It be exposed to nearly a red heat, it flilla 

 down into a soft powder, from parting with its 

 water of ciystalization, but is not decomposed. 

 It is still the sulphate of lime, has diminished about 

 one-fourth in heft,* and, consequently, worth about 

 one-fourth per ton more than our conmion gi'ound 

 plaster tor agricultural purposes. If the heat be 

 carried still higher, it is then decomposed and re- 

 solved into its elementary principles, and no longer 



vigorous by the plaster, and a large grovrth being | aflbrds any nutrition to vegetables. But this can- 

 turned under, a permanent manure is thus put upon | not be done without the addition of carbon or 

 the land, which manure I hardly think vv*ould have charcoal. 



been improved by passing through the barn yard. Now if these be facts, (and I think they are 

 By some farmers it isjthought to be good practice , susceptilile of demonstration) how is possible that 



to use plaster on the following crops, in the order 

 in which I place them: commencing with grass 

 land, break it up, plant it to corn, the nextyear 

 sow it to oats, the same fall sow it to wheat, the 

 next spring seed it Avith clover, pasture a i^aw years, 

 and again subject it to the plough ; thus maldng 

 the land by a comparatively small amount of labor, 

 produce three crops. 



The last requisition you make of me, is, that I 

 ehould " give such facts as it would be necessarj- 

 for a new begimier to larow, to use plaster to ad- 

 vantage. " 



Having occupied so much space in j'our paper 

 already, I will only caution the inexperienced 

 against buying plaster that has been kiln dried, 

 Can expedient sometimes resorted to by dealers in 

 me article to make it grind easy,) as it is supposed 

 to be injurious. It should be ground fine; the finer 

 the better. Finally, be cautious in adopting en- 

 tirely the opinions of other men, but experiment lor 

 yourself. Sow some lands caid leave others — 

 put plaster on some rows of corn and leave others 

 — in short, be cautious in the beginning, and a few 

 years of observation will enable you ever after- 

 wards to act knowingly. 



Feb. 26, 1834. « ostoadaga. 



simply heating plaster sufficient to diy the mois- 

 ture from the surface, without any change being 

 produced in its composition, can produce an injury', 

 or render it less nutricious? 



If there can be any reasonable reply given to 

 the above remarks, I should be glad to see it. 



CAMILLUS. 



GYPsrar not injured as sianure by being 



HEATED. 



From the Genesee Farmer. 



Mr. L. Tucker — In your paper of the 22d 

 March, is an article upon the subject of plaster, 

 signed " Onondaga." 



The writer has given some practical observa- 

 tions upon the subject, which I think are judicious; 

 but his concluding caution against the use of kihi- 

 dried plaster has neither foundation in science or 

 experience. 



In order to ascertain whether the process of 

 drjing plaster produces any effect upon its influ- 

 ence upon vegetation, it Avill be necessarj- to ex- 

 amine its nature, and the eflect ])roduced" by the 

 agency of caloric or heat upon its composition. 



Pure plaster (or g^i^sum) is a compound of sul- 



Fhuric acid and lime (or oxide of calcium) — and 

 should consider that the adchtion of any other 

 substance, would be considered an impurity, and 

 would (hminish its salutary influence upon vegeta- , 

 tion. It is found in nature in a state of crystali- 

 zation, and is in combination with water in about 

 three-fourths of the former, and one of the kitter. 



Extract from another part of the Genesee Fanner, on the samo 

 subject. 



I should have no apprehension that kiln-dried 

 plaster was damaged. I have assisted in heating 

 it to make it grincl easier, and have no recollection 

 that its efficacy was impaired. The lime and sul- 

 phuric acid, cannot be separated by heat alone, al- 

 though it ma}' be melted. At a low red heat, 

 indeed, it loses its water of crj-stalization; but it 

 readily recovers it; and I know of no reason for 

 believing that calcination can alter its properties 

 as a manure. a farmer. 



[The foregoing exh-acts fi-om the Genesee Farmer 

 serve to show the opposite opinions of practical farmers 

 as to the effect of heat on gj'psum. The reasoning of 

 " Camillus " is coiTectly founded on the chemical com- 

 position, and known properties, of gypsum. A moderate 

 degree of heat certainly deprives tliis substance of no- 

 thing but the water with which the otlier ingredients 

 were chemically combined; and it is not easy to con- 

 ceive, that the mere absence of a portion of water, which 

 is so abundant in the atmosphere and the soil, can lessen 

 the value of the manure. But, on the other hand, it 

 will not be safe to be giuded by theoretical reasons 

 alone, when deciding on tlie operation of a manure, 

 so inexplicable as that of g3-psum — the well estabhshed 

 great etiects of which, indeed, are altogether contrary 

 to what theory and reason would teach, if we had not 

 the louder facts, by which to decide on its value. It 

 has been a generallj^ prevailing opinion among practical 

 men, tliat the effect of gj7)sum was materially lessened 

 by the stone having been heated: but no accurate ex-' 

 periments have been made, (easy as they would be*to 

 make,) to decide the disputed question. It is import- 

 ant that proper experiments should be made for this 

 purpose: for the labor of pulverizing gj^sum is greatly 

 lessened by its being first moderately heated — and it is 

 desirable for farmers to use this facility, if it does no 



* Weight. 



