1835;] 



FARMERS' REGISTER. 



41 



scribing the precise locality, and from what part 

 of the bed each was taken, could give but little if 

 any information, even if selected by the geologist 

 himself But if selected by othes— -either igno- 

 rance, or carelessness, or self-interest, or a desire 

 of a proprietor to show better marl than others, 

 might cause an exhibition of a very rich speci- 

 men from a bed generally much poorer. For 

 these several reasons, but little importance can be 

 attached to the results presented in the table of 

 calcareous marls — and so far as our latter objec- 

 tions apply, the fault is not the author's, (nor 

 the proprietor's) but of the plan fixed by law 

 under which he acted, and by which he was 

 bound to be governed. In making it the duty of 

 the geological surveyor to analyze the various spe- 

 cimens of marl, soil, &c. sent him by any proprie- 

 tors, he was left no choice but to perform a vast 

 deal of arduous, yet mechanical, and often useless 

 labor, of which the results must be necessarily 

 mostly mere rubbish. The worker of a marl pit 

 who desires to know its average strength, should 

 take specimens carefully and fairly selected at va- 

 rious depths, and certainly at every change of ap- 

 pearance. A single digging may sometimes re- 

 quire a dozen trials, if great accuracy is deemed 

 necessary. But after tins is done, the same bed 

 might be worked for years, without showing a 

 variation worth notice, from the same general cha- 

 racter, or average strength. And indeed, the 

 practised eye may easily know the same bed 

 though found at some miles distance, and may be 

 satisfied with the analyses made from the earlier 

 known locality. 



The observations made by the author through 

 the report are as often agricultural as geological, 

 and on that account might be supposed to pro- 

 mise the more value, to the farmers of Maryland. 

 But the duty was of course confided to one cho- 

 sen as a geologist and chemist, and not as an agri- 

 culturist — and however desirable the union of all 

 three branches of knowledge may be in the indi- 

 vidual appointed to make a geological survey, it is 

 not to be looked for. But it may perhaps deserve 

 consideration whether the general and most im- 

 portant objects of such a survey would not be ad- 

 vanced by the aid of an intelligent agriculturist 

 to the more scientific labors of the geologist, and 

 which should be confined to drawing these practi- 

 cal deductions for which the man of science is 

 rarely qualified. If one of the many enlightened 

 farmers of the Eastern Shore of Maryland had 

 for this purpose been associated with the geologist 

 the latter might have been saved much of the 

 trouble of making observations of matters of prac- 

 tical agriculture, and that branch of* the subject 

 could have been made far more full, correct and 

 useful. 



It seems to be a remarkable deficiency in the 

 report, that though it was made by the law part of 

 the surveyor's duty "to analyze and ascertain the 

 qualities and properties of all specimens of miner- 

 al substances, or soil, left at his office or residence, 

 for that purpose by any citizen of the state, and 

 taken from any portion of the territory of the 

 state" — that not a single analysis of any soil is 

 given. Nor is there any indication of the con- 

 stituent parts, other than such as the eye of an un- 

 learned observer might direct, except that it is in- 

 cidentally and slightly observed (p. 21) that the 



Vol. Ill— 6 



soil lying over the marl "is never found to contain 

 calcareous particles." If the author meant to con- 

 vey (as is maintained generally in the Essay on 

 on Calcareous Manures — ) that the soil is gener- 

 ally, if not entirely destitute of any portion of car- 

 bonate of lime — -it would have been gratifying if 

 he had been more particular, and had commented 

 on the remarkable difference in that respect be- 

 tween the soils of that region, and the usual con- 

 stitution of most of those soils in Europe of which 

 any knowledge is to be gained from books. 



In furnishing directions for working marl pits, 

 and applying marl, and making observations on 

 the practical effects of the manure, the author 

 quotes largely from the Essay on Calcareous Ma- 

 nures, to which work due credit is given. We 

 will pass by this part of the report, and proceed to 

 the account of the beds of marl, and the green 

 sand formation of the Western Shore of Mary- 

 land. 



"Principal localities of the shell-marl deposiles on the 

 Potomac, their constitution, relative value, and use. 



"As the use of marl has scarcely been at all resorted 

 to on the Western Shore of Maryland— although from 

 its quality as it there occurs, and the condition of the 

 soil by which it is overlaid, its application would be of 

 the greatest benefit— it is deemed a matter of infinite 

 importance to indicate, as precisely as the extent of 

 the examinations so far made will permit, the situations 

 in which it has been discovered, or where it is likely to 

 be found by proper research. 



"A very extensive and very accessible deposite of 

 marl occurs near Piscatawa, on the north side of the 

 creek. The bed is overlaid by a thick crust of indu- 

 rated shells and sand, that can, however, be easily re- 

 moved, and beneath which is the friable marl in an ex- 

 cellent condition for immediate use. The analysis of 

 this marl is given at No. 42 of the table. No. 43 indi- 

 cates the constitution of a marl occurring under similar 

 circumstances with the preceding, at Upper Marlbo- 

 rough. These two localities are to be considered in fact, 

 only the most prominent points of a great fossil deposite, 

 extending from Fort Washington to the west branch 

 of the Patuxent. This deposite will, no doubt, be soon 

 discovered on intermediate spots, from which it can be 

 extracted with equal facilities, so as more generally to 

 diffuse the benefits which its application to the soil 

 must inevitably produce. The situations that may be 

 indicated, as those where it is most likely to make its 

 appearance, are along the small branches that make 

 into the Piscatawa, on either side. The village of 

 Piscatawa is based on a bed of marl, and in its vicin- 

 ity, at a place called the marl bottom, the material has 

 been employed with the usual success. We are in- 

 debted to Dominick Young, Esq. for this perhaps soli- 

 tary, experiment made on the Western Shore of Ma- 

 ryland, on the good effects of marl.- Much regret is 

 felt, that, owing to the absence of that gentleman from 

 his plantation, a full account of the result of his expe- 

 rience was not obtained. It is desirable indeed to as- 

 certain the operation of marl on differently constituted 

 soils, and a knowledge of their natural fertility or sus- 

 ceptibilities — never better discovered than by agricul- 

 tural experiments — is essential, in order to arrive at 

 safe conclusions. The directions given in a former 

 part of this report as to the manner of employing the 

 marl on the Eastern Shore, will no doubt apply here: 

 at all events it will be perfectly safe to follow them on 

 wheat and corn lands; but we possess, as yet, no infor- 

 mation as to its effects on tobacco lands. Reasoning 

 from analogy, no mischief can be apprehended from 

 the use of marl on these as on other lands; but in order 

 to direct its proper application, as to quantify especial- 

 ly, we should be aided by at least a few positive re- 



