1837.] 



FARIMERS' REGISTER. 



'19 



and carbonate of magnesia, and ha? often the pro- 

 ])erties of a hydraulic cement. The following is 

 tlie composition of one of several specimens of 

 this varirty which were analyzed. It was obtained 

 from a hill, one mile north of Staunton. One hun- 

 dred grains contain 



Carbonate of lime, 49.50 



Carbonate of magnesia, 33.87 



Mlica, ^ ' 7.50 



Oxide of iron and alumina, 2.83 

 The rock ol a light greyLsh blue color, and of 

 very compact texture, almost always contains a 

 large pro|)oriioti of silica, as well as carbonate ol 

 magnesia. The hydraulic lime made at Shepherds- 

 town, i'^ generally procured from this rock. The fol- 

 lowinir is theconiposition ofa specimen of this kind, 

 ti-om Reynolds' quarry, liut it is to be observed, 

 that even from this neij-hborhood, the cement 

 roi-ks exhibit a great diversity in the proportion of 

 their constituents. One hundred grains contain 

 Carbonate of lime, 32.17 



Carbonate of magnesia, 18.36 



Silica, 38.93 



Ox. iron and alumina, 4.17 



The rock to be used in preparing cement for the 

 locks of the James river canal, is of this kind. It 

 iri obtained in Rockbridge county, and contains 

 Carbonate of lime. ' 38.33 



Carbonate of magnesia, 16.30 



Silica^ 36.60 



Ox. iron and alumina, 6.33 



It will appear, from what has been stated, in re- 

 gard to the aspect of the several varieties of lime- 

 stone above described, that any careful observer 

 may in general dislingiiish between those rocks 

 which are magnesian and those which are not. 

 This is a matierof no small importance, especially 

 in the agricultural employment of the lime, since, 

 if not actually injurious, as was once supposed, the 

 magnesia is at best an efficient substitute for lime. 

 Moreover, the rocks containing it are more diffi- 

 cult to burn than the others, and unless when 

 hydraulic, the lime they yield is not so well adapt- 

 ed for mortar. 



The greatabundancsof thedark blue limestone, 

 so admirably suited to the uses of the farmer, holds 

 out a strong inducement to the employment of 

 lime .upon the soil. In my former report, I at- 

 tempted to move the mistaken impression, that the 

 land of limestone regions is already suifiiuendy 

 imbued with calcareous matter, by appealing to 

 the results of analysis ; and I would now repeat 

 the observations then made, as having been con- 

 firmed by further examination. 



There cannot be any fiict in practical agricul- 

 ture more clearly proved, than the beneficial action 

 of lime upon the soil of limestone regions, such as 

 our valley. Why then is it not extensively used 

 by the fiirmers in that portion of the state? With 

 so sure and inexhaustible a means of improvement, 

 (every where around them,) every hill and valley 

 might be made productive. This is one day to be 

 the result of the systematic and general use of" 

 lime, aided by an improved scheme ol" agriculture. 

 But I would gladly speed the progress of amelio- 

 ration, by pointing to the invaluable resource 

 which nature has provided for the improvement of 

 this country, and by expostulating earnestly, on 

 grounds of science and experience, with those who 

 are disposed to neglect the boon. 



The reconnoissance of the south-western coun- 



ties, embi-aced a rapid examination of parts of 

 Grayson, Wythe, Montgomery, Smyth and Rus- 

 sell, and included a more detailed investigation of 

 the lead, plaster and salt of tlus region. 



The lead mines are situated near Ci-ipple creek, 

 about four miles from Poplar Camp furnace, in a 

 direction a little south of west. They are wiihin 

 half a mile of the sout!i bank of New river, and 

 about one and a half fi'oni the base of the Poplar 

 Camp or Iron mountain. The ore occurs in a sili- 

 ceous limestone generally ofa white or grey color, 

 though sometimes blue. The veins are irregular 

 in dip and direction, frequently turning very 

 abruptly, and seriding off leads or branches. On 

 either sitle of the ore, the enclosing material con- 

 tinues of a soft texture, as far as the walls of lime- 

 stone enclosing the whole, wliich vary in their dis- 

 tance ll-om each other. On the upper side of the 

 vein, is L'enerally found a reddish clay. On the 

 lower side, i^; a firmer material, containing crystals 

 of phosphate of lead and other niiiticrs. 'J'his, 

 the workmen here, as in Europe, call cliidver, and 

 thev reject it as of no value. 



The vein proper, is in general twelve inches 

 thick, and contains the following ores of lead: 



1. Compact sulphuret or blue ore. 



2. Compact carbonare or grey ore. 



3. Crystallized carbonate — or Cat's tooth. 



4. Mixture of carbonate and oxide — brown and 

 red ore. 



5. Finely divided sulphuret — black ore. 



The sul[)huret, or blue ore, occurs only in some 

 parts of the vein in irregular masses or cups as 

 they are called, and does not occupy one half of 

 the productive portion of the vein. The other 

 ores occur along side of it,' and are mingled with 

 it. The adjacent limestone is sometimes in a soft 

 and crumbly condition, and curiously spotted — 

 sometimes in the form ofa beautiful white spar 

 containing crystals of cubical galena. 



There are six openings at present wrought, each 

 having drifts below the surface at various depths, 

 from 30 to 120 feet. These are all comprised 

 within a space of less than 150 yards square. To 

 the S. \V. are numerous pits, ti-om which ore was 

 extracted in former years. The entire distance 

 through which the lead has been traced and 

 wrought in this vicinit}^, is about half a mile. 

 The general direction of the veins, is nearly N. 

 H and S. W. One of the same description has 

 been found at several points to the N. E., and 

 among others at Mr. Sawyers', on Reed creek, 

 about seven miles from the mines. Blue ore has 

 also been found in small quantity on Mr. Gra- 

 ham's land, at an equal distance, in a due north 

 direction. Whether a valuable amount of the ore 

 exists at either of these places, or in any of the 

 numerous localities in other and distant parts of 

 the valley in which specimens have been disco- 

 vered, it is impossible to say, without much further 

 investigation. 



The extent of the workable ore, at the mines 

 just described, appears from the indications observ- 

 ed, to l)e very considerable, and it were greaily 

 to be desired, that a systematic mining of these 

 veins were undertaken upon a scale commensurate 

 with their value. At present^ a wasteful method 

 of excavation is threatening serious injury to the 

 interests of future minini? operations in this region, 

 and, if persevered in, will destroy the usefulness of 

 many portions of the veins now worked, by ren- 



