Jtt8Q, H8 1 ,»«-.:, S183 1 . 8H3 a ] [RO.N in kiii>, :»i:-, 



similar to this occurs in a well dug on the plantation of Mr. Holland, S. 35, 

 T. 6, It. 3 E., near Brandon. — The water of the Artesian Springs in Madison, 

 is of the same character; and ano'her alum spring, which has acquired spine 

 reputation in the neighboring counties, is situated about two miles south-west 

 of Grenada. In the neighborhood of such springs, a mixture of alum with 

 other salts is frequently seen, as a white covering ("efflorescence") on the sur- 

 face of the clays (II LSI). I 



380. Of the part taken by Iron and Manganese, the two last elements of out 

 list, in c loring- days and soils, I have already spoken. Manganese, though 

 almost universally present in soils, is g< norally so in very minute quantities, so- 

 as to es ape 'he eye, and leave its pus nee to be demonstrated by chemical 

 reagents. Occasionally, in this State, Oxide of Manganese may be observed 

 farming curiously ramified designs (dendrites), resembling mosses or diminutive 

 trees, on thj e'eaved su<"fac3S of gray and white sandstones and l'mestones. 

 These figures are frequently mistaken for fossil plants ; but they have no co?a- 

 nect'on with such, being simply strings of crystals, formed somewhat in the- 

 manner of the figures on frozen windows. 



381. Iron is one of the most widely diffused substances with which we are 

 acquainted. It would be difficult indeed, in common life, to pick up anything 

 whatsoever that should not contain a trace at least of iron — unless, perhaps, jit 

 had I een purposely purified. The allies of almost all vegetables contain it; ss> 

 do all soils, clays, and sands ; so do all kinds of glass. Even the metals, copper, 

 tin> zinc, lead, and silver, such as they are known to common life, contain cer- 

 tain amounts of it ; often very minute, but still discoverable by chemical meafi&. 



382. Oxide of iron in combination with water (Jnjdrated peroxide of irony, ©y 

 iron rust,is the compound most commonly occurring. It is found almost pure, 

 as yellow ochre (which is usually, however, a mixture of oxide and of clay); it 

 imparts the yellow or orange tints to clays, sands, soils and subsoils ; to tfoe 

 * red lands" of Pontotoc, Chickasaw and other counties ; to the yellow loans 

 lands of the two ranges of counties bordering the Mississippi bottom, whWls 

 form the rich agricultural regions of Lafayette, Yallabusha, Carroll, Holmes^, 

 Madison, liinds and other counties. It forms the cement which binds together 

 the grains of .-and in our red, brown or "black" sandstone, found more or less 

 all over the State (H 11, if.); sometimes the cement so far predominates over ibe 

 tend, that the material would be valuable as iron ore, but for its being too much 

 scattered to allow ot profitable smelting (U 74 * ). Nodules of brown hon owe, 

 of various degrees of purity, are the unfailing surface indication of the 

 elays of the Lignitic formation of North Mississippi (If 42). 



383 1 . Iron in Soils — The presence of a large surplus of the peroxide of iroai 

 (or iron rust) in soils (which may generally be pretty correctly judged of by tW 

 intensity of the color), does not apper to exert any very characteristic influence 

 on vege ation. save such as may be owing to its powerful attraction for mois- 

 ture and ammonia (which it shares with clays), and the influence of its color 

 on the absorption of heat from the sun's rays. A small amount of iron seems 

 to be indispensable to the vigorous growth o' most cultivated plants, for on soUs 

 artificially formed without the addition of iron, these vegetables languished and 

 drooped, and the subsequent addition to the soil of a small amount of iron, 

 seemed to produce elfects similar to that which the preparations ot ijixn 

 used as tonics in medical practice, produce on the human system, viz :. a 

 geneial invigoration of the vegetative energies. But such a soil had to be artifi- 

 cially lormed, as above stated ; for in natme it might be difficult to find any sail 

 not contain ng a supply of iron sufficiently laige for ihe use of plants. 



383 2 . While an excess ot iron in the shape of the compound heretofore 

 mentioned (viz : the by d rated peroxide of iron) may be present without any 

 injury to vegetation, the same is not true with reference to the other combinatifiat 

 of iron with oxygen (containing less of the latter element than the peroxide,.©* 

 iron rust): the protoxide. And since this difference has an important bearing «sa> 



