426 



FARMERS' REGISTER— MAGNESIA. 



by filtering. Of course, this brought ofF all the mag- 

 nesia, in the form of Epsom salts, and with the clay 

 left the lime, rendered insoluble (or nearly so) by being 

 converted to gypsvmi. This showed clearly that mag- 

 nesia was present, and in large quantity. It was pre- 

 cipitated from the filtered solution by adding carbonate of 

 potash. In another trial, instead of being precipitated, 

 it was exhibited as Epsom Salts (in solution) of which 

 the peculiar nauseous bitter taste sufficiently proved its 

 kind, and of course the existence of the magnesia from 

 which it was formed. This is not the best method of 

 finding magnesia — but may be useful when better 

 means cannot be used. 



This statement has been made more in detail than 

 necessary, if the discovery of this kind of marl is to 

 end where it is, or if the benefit of a single landholder 

 only was concerned. But it seems reasonable to believe 

 that this kind of earth may be foixnd to stretch over a 

 large part of the granite region where this has been 

 found — and it may be advantageous to many to have 

 the clearest description of the appearance and chemical 

 character of an earth, which promises so little to the 

 eye. 



Dr. Meaux writes that the farm on which the disco- 

 very has been made, has been thereby enhanced imme- 

 diately one third in price. A much greater advance 

 ought to be made, if this resource for fertilization is in 

 sufficient abundance. If the magnesia is supposed to 

 be worthless, and to do neither good nor harm as ma- 

 nure, the marl is still rich enough in calcareous earth to 

 double at once the value of any farm on which it is dis- 

 covered — and to quadruple it by being used. But 

 though very little if any thing is known of the opera- 

 tion of carbonate of magnesia on soils, and nothing but 

 actual experiment can determine it, still there is every 

 reason to suppose it to act in a similar manner with cal- 

 careous earth, which it so nearly resembles in chemical 

 qualities. And if the magnesia is equal in value to 

 lime (both being carbonated or mild) which would make 

 the strength of the manure 85-100, then it will be not 

 only used where discovered, but may be profitably 

 transported for matun-e to considerable distances. 



There has been much controversy respecting the ac- 

 tion of magnesia as manure — but its effects when caus- 

 tic, as when calcined with quick-lime, were only con- 

 sidered, and little or no attention paid to it in its carbo- 

 nated, or mild form. But defective as they are in this 

 respect, such opinions as have been expressed will now 

 be interesting to many of our readers, and we shall ex- 

 tract them from some of the most intelligent writers 

 on the subject. Though but little has been published 

 as to the effects of carbonate of magnesia, (as present- 

 ed in tliis magnesian marl,) the testimony and opinions 

 expressed are in favor of its being valuable as manure. 

 The discovery of this marlwith such remarkable quali- 

 ties, offers strong encouragement to othei'S to search 

 ^or such beds, and try their value themselves by che- 

 mical tests. A few drops of muriatic acid in this case 

 served to disclose a concealed and invisible value, which 

 will be worth thousands of dollars to the owner. Nor 

 need such examinations be limited to so incomplete a 

 trial as first indicated that the earth was calcareous. 

 Almost any person by attending to the directions which 

 have been given in several different works (Davy's Ag- 



ricultural Chemistry for one,) may soon learn to ana- 

 lyze marls with sufficient accuracy. This knowledge, 

 and its practice, will be valuable to every person who is 

 using calcareous manures ; and the same value cannot 

 be as well supplied by any degree of trouble imposed 

 for that purpose on another and distant operator. 



The discovery of this rich calcareous bed in the gra- 

 nite range, together with the great extent of the argillace- 

 ous marl discovered by Dr. Morton, and announced in 

 the first number of the Farmers' Register, furnish good 

 reasons for believing that every region of Virginia is 

 provided by nature with sources from which to obtain 

 calcareous manures in abundance. The consideration 

 of the ultimate results to be expected, if this hope in- 

 deed is well founded, opens a prospective view of agri- 

 cultural improvement and national benefit, which if ex- 

 liibited, perhaps would not (at present) add to any re- 

 putation we may have for possessing soundness of judg- 

 ment. We will therefore close these remarks, with re- 

 peating a suggestion which we have before made. If 

 the legislature would employ some scientific and practi- 

 cal geologist, having a competent knowledge of agricul- 

 tural chemistry, to survey the whole territory of Virgi- . 

 nia, and report all discoveries of minerals, whether ma- 

 nures, metallic ores, or materials for manufactures, there 

 can be little doubt but that the gain to the common- 

 wealth would exceed the expense tenfold. If the dis- 

 coveries made by Dr. Morton, and that which has pro- 

 duced these comments, had been due to such an agent 

 employed by the government, their value alone would 

 overpay the salary that would procure the scientific 

 attainments and laborious services required for the 

 faithful jierformance of such duties for a year. 



EXTRACTS FROM SEVERAL AUTHORS, SHOW- 

 IMG THEIR OPINIONS OF THE EFFECTS OF 

 MAGNESIA, IN DIFFERENT FORMS, ON SOILS. 

 I. 



The question considered, whether Magnesian Livie- 

 stone is pernicious to vegetation ? 



From the [EtlinburghJ Farmers' Magazine. 



During two or three years past I seldom return- 

 ed to til is city, from my laborious peregrinations 

 through the liighlands and isles, without having my 

 ears perpetually stunned with violent invectives 

 against the use of lime, which contains magnesia, 

 as manure. Some zealous friends of mine (whose 

 zeal exceeds their knowledge) suggested the 

 propriety of analyzing all the limestone quarries 

 in their vicinage, and, if found to contain a parti- 

 cle of magnesia, proposed that they should be shut 

 up by act of Parliament, and prevented from poi- 

 soning the crops in their neighborhood. 



In fact, among your agriculturists, the magnesice- 

 phobia seems to be the order of the day : and they 

 appear to be as much terrified at magnesia, as a 

 helpless traveller, like me, is sometimes at mad 

 dogs. 



My peregrinations having precluded me from 

 perusing any of the original publications which 

 excited this magnesiae-phobia, I beg leave to offer 

 a few remarks on an Essay, signed Tyro, York- 

 shire, 1804. Vol. V, p. 272. 



As far as I can learn, the magnesiae-phobia com- 

 menced in Yorkshire, and has spread by repeated 



