1837.] 



FARMERS' REGISTER. 



715 



and character of the two, while it leads us to infer 

 the action of like chemical agencies upon both, 

 assures us of a siaiilarity in their agricultural 

 eti'ects. 



The eocene marls of the peninsula,, present 

 much diversity of composition. Whilst in some 

 localities, the shelly matter lc,)rms a very considera- 

 ble part of the mass, in others. Utile or none of it 

 occurs. The green sand ofen Ibrms a prominent 

 ingredient, and is in no case absent, though fre- 

 quently the amount of it is very inconsiderable. 

 Gypsum is also occasionally to be met with; and 

 this, as well as the other sulphates, is not excluded 

 from the beds containing shells. A minute analy- 

 sis of some of the more important of l!iese marls 

 is now in progress, but the research is one requir- 

 ing much time for its completion. 



It may be useful to state, that in general, the 

 shelly strata of the eocene, in this district, do not 

 contain more than from ten to fifteen percent, of 

 carbonate of lime, and that in many instances, 

 where the shells are quite conspicuous, the propor- 

 tion is less than one half of this. In the shell 

 rock, such as occurs in several places on the Poto- 

 mac, as much as eighty-two per cent, has been 

 found. 



It would therefore appear, that while in some 

 instances, there is a sutbcient amount of carbonate 

 of lime in the mass lo give it the character of a 

 rather poor calcareous marl, the proportion of this 

 ingredient in general is too inconsiderable to im- 

 part any high deo;ree of agricultural value. For 

 nmch of the benefit derived from the application 

 ot' these substances to the soil, we nmst look to the 

 green sand, gypsum, and perhaps other ingre- 

 dients which they contain. Experiments now in 

 progress with some of tlie varieties containing lit- 

 tle or no shelly matter, mdicate decidedly benefi- 

 cial results; and there is but little reason to doubt 

 that more extensive trials of these materials, con- 

 ducted with judgment and caution, will confirm 

 the views at present entertained ot" their capacity 

 of being highly usetijl in agriculture. 



Fropi the absence of shelly matter in the strata 

 of Meiocene and Eocene above referred to, they 

 have hitherto been considered as entirely destitute 

 of value. The liict now made known ol' their 

 containing, nearly in every case, a notable amount 

 of gypsum, must therelbre be looked upon as an 

 interesting discovery, and should the observations 

 already made upon the fertilizino; eifects of the 

 material of these beds, be sustained by a wider 

 and more varied experience, our views of the agri- 

 cultural resources of the eastern portion of our 

 state will be greatly and cheeringly enlarged. 

 Believing that such is to be the result of further 

 experiments on the subject. I look with pleasin<r 

 anticipation to the time when the invaluable shell 

 marl of the country, will not be without a substi- 

 tute in those districts to which it has been denied, 

 and when almost every ravine in eastern Virginia, 

 will be resorted to for materials to improve the pro- 

 ductiveness of the soil. 



The researches in the counties bordering on the 

 Rappahannock to the south, were chiefly confined 

 to an inspection of localities of marl, and the exa- 

 mination of the strata associated with it, in several 

 of the more important points. The numerous spe- 

 cimens of the Meiocene marl which were collected 

 iu the reconnoissance, have been submitted to 

 analysis, and with the same general results as 



have been stated in regard to the marls of the 

 Neck; the pulverulent and light-colored varieties 

 always yielding a much larger per ceniage of car- 

 bonate of lime than the blue marl, and so'melimes, 

 as in the case of sfiecimens (lorn JNir. Oaks'g, and 

 other places in Middlesex, amounting lo about 80 

 per cent. Gypseous and sulphurclied clays were 

 Ibund here as in the Neck ; and at some points im- 

 mediately on the river, the sclenite was discovered 

 iu conspicuous crystals. An analysis of some of 

 these gypseous clays, gave iiom 8 to 10 per cent, 

 ot" this ingredient. 



Belbre concluding this sketch of the investiga- 

 tions in the tertiary region during the past year, 

 it maj' be well to remark, that in the event of an 

 ampler organization of the means of exploration, 

 urgently demanded by the survey, the revision of 

 the ground already traversed will be aided by the 

 employment of a boat built and equipi;ed for the 

 service. With such facilities, the exploration, in 

 dislricts hitherto unexamined, will be carried on 

 with increased accuracy and speed. 



The researches which were made in the bitumi- 

 nous coal fields of Henrico, Goochland, ^-c. were 

 in the first place directed to the determination of 

 the boundaries of the region in which the coal 

 measures occur. With this view, it was explored 

 by transverse lines, and throuidiout its entire cir- 

 cuit ; but further examinations are required to as- 

 certain its extent and structure, with the degree of 

 accuracy necc'^sary to represent it on the map. 

 And belbre this delineation can be usefully made, 

 the important errors in this portion of the map 

 will require to be corrected. 



All the important workings for coal, together 

 with a large number of shafts or disjginijs ot minor 

 interest, were examined; but additional investiga- 

 tions are required lo secure that exact knowledge 

 of the complicated structure of" these coal fields, 

 which may serve, hereafter, as a guide lo enter- 

 prises in this region. I t'eel safe, Itowever, in re- 

 marking that the observations thus far made, 

 whilst they indicate that the region containing 

 coal is more extensive than I had supposed — are 

 calculated to strengthen the opinion, that in no 

 part of ihe basin is the depth of the coal so great 

 as from a view of the directions of its out-crop 

 would be supposed— and if, as is probably the case, 

 the floor upon which it rests is of so undulating a 

 figure, as in some measure to divide the region 

 into several basins — there is a reasonable hope of 

 reaching this mineral at comparatively moderate 

 depths, even in the centre of the field. 



Althouijh these coals have long been extensive- 

 ly in use lor domestic and manufacturing purposes, 

 no systematic investigation of their chemical com- 

 position has hitherto been attempted, nor have any 

 jast data been lurnished for comparing them with 

 the coals of other regions, either in this country or 

 abroad. The minute investigations on this sub- 

 ject, in which I am now engatjed, have already 

 made me accurately acquainted with the compo- 

 sition and healing powers of upwards of" twenty of 

 these coals, and I feel no hesitation in sayinar, in 

 view of these results, that I am prepared to vindi- 

 cate their claim to a very high rank in comparison 

 with the coals of most other parts of the world. 

 Without entering into details, it may be useful to 

 stale, that in the specimens hitherto examined, the 

 amount ol' bituminous matter, varied from 27 to 38 

 per cent, of the whole, the ash in general from 2 



