to be identical with the butyrine of butter, and like it is decomposed by potash, with the formation of glycerine and a butyrate. Among the other glycerides are oleine, that of castor oil, and some more which have been but partially studied. Oleine undergoes a singular change by the action of nitrous acid or protonitrate of mercury; when a few bubbles of nitrous acid gas are passed through it, it solidifies after a short time into a granular mass, which when saponified affords a white crystalline acid, identical in composition with the liquid oleic acid. Castor oil yields a similar result with nitrous acid, and the same effect is. produced upon it by sulphurous acid gas. The glycerids are characterized by evolving the pungent oder of acroleine when decomposed by heat.

acids.

Alkaloids.-The organic alkaloids are a class of nitrogenized bodies which unite directly with Ammonia may be taken as the representative of them. This substance combines with nitric acid NHO, and with the nitrate of copper NCu O in both cases forming neutral salts. As the compounds of ammonia with acids present a close resemblance to the salts of potash, it was proposed to regard them as containing a compound metal NH,, which replaces the hydrogen. The nitrate of ammonia NHO, NH,, is upon this view N (NH,)O,, assimilated to nitrate of potash NKO,. But this view is sustained but by few analogies. Since ammonia unites in the same manner with acids and their salts, the latter as the ammonia-nitrate of copper NCu O, NH, must be assumed to contain another compound metal NH, Cu; and from the complete similarity between ammonia and the vegetable alkaloids, their salts according to this theory must each contain a compound metal which is composed of the elements of the alkaloid plus an equivalent of hydrogen. In view of the immense number of hypothetical compounds which this theory requires, and the imperfect analogy upon which it is founded, it is preferable to regard the alkaloids and ammonia as bodies which unite directly with acids and metallic salts. Strychnine, for example, combines with nitric acid to form the compound C,, H,, N, O,, NHO,, and with nitrate of silver C2, H2, N, O,, NAg O

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2

3.

These bodies may be divided into two classes; the first are those composed of carbon, hydrogen, and nitrogen. If the equivalent of these is low they are volatile liquids, but when this is more elevated they are often crystalline and not volatile without decomposition. Among them are anilene, quinoleine, nicotine, and conine, with naphthalidam and sinapoline. It is probable that none of these exist ready formed in plants, for although nicotine is obtained when tobacco is distilled with a solution of potash, late researches have shown that it is formed in the process, and the same is probably true of conine. These alkaloids,

at least the four first named, are very poisonous. The second class includes those which contain oxygen; these are all solid and crystallizable, and with but a few exceptions, obtained from plants, of which they constitute the active principles. Urea is the only alkaloid which is found in the animal organism, and the only natural one which we have been able to reproduce artificially. The action of ammonia upon oil of mustard and of sulphuretted and seleniuretted hydrogen and ammonia upon aldehyde, afford alkaloids in which sulphur and selenium replace oxygen. Alkarsine is one in which acesenic replaces nitrogen.

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M. Hoffmann, in his late beautiful researches, has discovered several new alkaloids derived from anilene C, H, N, by a replacement of its hydrogen. Chlorainline and bichlorainlene correspond to anilene in which one or two equivalents of hydrogen have been replaced by chlorine, and two corresponding species are obtained which contain bromine. In nitranilene we have a beautiful instance of substitution by the residue of nitric acid. It is anilene in which NHO, -O replaces H,, and is represented by C, (H, NHO,)N; although it contains the elements of a powerful acid its neutralizing power is the same as anilene itself.

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The researches of M. Gerhardt have shown that the alkaloids, like ammonia, act by their hydrogen upon oxydized bodies to form compounds which correspond precisely to the amides. The oxalate of anilene when decomposed by heat loses two equivalents of water, and forms oxanilide, which, like oxamide, regenerates oxalic acid and the alkaloids by the influence of acids or alkalies. The anilide of formic acid has also been obtained, and sulphanilic acid which is monobasic, and corresponds to the oxamic. The oraluric acid is a coupled acid in which urea sustains the same relation as ammonia in the oxamic; in its decomposition it assumes the elements of water and regenerates oxalic acid and urea.

cesses.

The artificial alkaloids are formed by a great variety of proThe action of fused hydrate of potash upon indigo or isatine results in the abstraction of its oxygen and a portion of carbon, which is oxydized at the expense of the water, and forms carbonate of potash, while anilene and hydrogen gas are evolved. The oxygenized alkaloids, quinine, cinchonine, and strychnine, by the same process afford quinoleine. The action of nascent hydrogen upon the nitric species of hydro-carbons has furnished many new alkaloids. When a solution of nitro-benzene C, H, NO, is mixed with dilute sulphuric acid and zinc, the liberated hydrogen combines with it and forms anilene with the liberation of two equivalents of water C, H, NO,+6H= C, H, N+2H,,O. The same result is obtained by the action of sulphuretted hydrogen, the sulphur separating. It is from the decomposition of binitric benzene that nitraniline is obtained.

These bodies are often isomeric with amides of known substances, and M. Gerhardt regards them as all amidized species of some nonazotized substances, but differing from ordinary amides in not regenerating ammonia by the action of alkalies or acids. Mr. Fownes has observed that the amides of furfurol and benzoilol, which regenerate ammonia and the oils by the action of acids, may be boiled with a dilute solution of potash without evolving ammonia. On cooling, the alkaline solutions deposit crystals which have the same composition as the original amides; they are no longer decomposed by acids, but combine with them and form well characterized salts, being converted into alkaloids, (furfuroline and benzoline, or amarine of Laurent.) The alkaloids, melamine and ammeline, obtained by Liebig from the decomposition of sulphocyanate of ammonia, correspond to the amides of cyanuric acid, and by long boiling with a dilute acid, are decomposed into salts of ammonia and cyanuric acid. The direct action of ammonia upon organic substances sometimes produces alkaloids; amarine, the benzoline of Fownes, which is isomeric with hydrobenzamide, was obtained by Laurent by the action of ammonia upon a solution of the oil. Phenol combines directly with ammonia at ordinary temperatures, but if the compound is heated for some time in a closed tube, it gives up the elements of water and forms aniline, which corresponds to the amide of phenol. These compounds are designated by M. Gerhardt as alkalamides.

There are many other subjects in this portion of the work which it would be interesting to notice, as the characters of the carburets of hydrogen, their constitution and boiling points; but this sketch has already exceeded its proposed limits, and their consideration must be reserved for another time.

The third part of the first volume is devoted to the consideration of the effects of heat and other reagents upon organic substances, and the nature of the changes which they undergo. This is followed by a particular description of all organic bodies, arranged in the order of their families. The latter part of the second volume contains an exposition of the theory of homologues, with an ingenious application of the principles developed in the previous portions of the work, to a natural classification of organic substances with reference to their origin and derivation from each other, and which may form the subject of another notice.

In conclusion, we recommend to all interested in the progress of chemistry, the study of this work, which by its profound research, grand generalizations, and beautiful system, establishes the title of its talented author, to a high rank among the philosophers of the age.

SECOND SERIES, Vol. IV, No. 11.—Sept., 1847.

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ART. XV. On the relative Age and Position of the so-called Nummulite Limestone of Alabama; by C. LYELL, F.R.S. and V.P.G.S.

In a former paper, published in the Quarterly Journal of the Geological Society of London,* I stated that the limestone containing abundantly the Nummulites Mantelli, Morton, which occurs near Suggesville, Clarksville, and other places between the rivers Alabama and Tombeckbee in the state of Alabama, was a member of the eocene tertiary group, and that so far from constituting any part of the cretaceous formation as had formerly been imagined, it holds in reality a place high up in the eocene series of the South. In the same memoir I gave a section extending from Claiborne through Suggesville and Macon to the west of Clarksville, Alabama, in which the position of the socalled Nummulite limestone was explained. It was stated to be newer than all the beds of the well-known Claiborne bluff, and I mentioned that "the bones of the gigantic cetacean called Zeuglodon by Owen, were everywhere found in Clarke county, in a limestone below the level of the Nummulite rock, and above the beds which contain the greater number of perfectly preserved cocene shells, such as Cardita, Planicosta and others."+

At the time that my first communication was written, I had not finished my explorings in Alabama nor visited St. Stephen's bluff on the Tombeckbee river, where I afterwards obtained additional proofs of the order of superposition above indicated. Nor had I then compared the eocene strata at Vicksburg with those of Jackson in the state of Mississippi, which throw light on the same question of relative position. Before adverting to these last mentioned localities, I will first offer a few observations on the country between Claiborne and Clarksville, for I understand that doubts have been lately thrown on the correctness of the views which I have expressed relatively to the true age and place in the series to be assigned to the "rotten limestone of Alabama,” and the associated rock in which the fossil first named Nummulites Mantelli, by Morton, abounds.‡

Before restating the grounds of my former opinion and corroborating it with fresh proofs, it may be well to say something of the nature and zoological relations of the discoid bodies from Alabama which have passed under the name of Nummulites and

*Vol. ii, p. 405, May, 1846.

t Quart. Journ. Geol. Soc., vol. ii, p. 409, May, 1846.

Sir R. I. Murchison announced to the Geological Society of London, at their meeting, May 26th, 1847, that he had just received a letter from M. Agassiz, in which he stated that M. Desor had clearly shown that the rotten limestone of Alabama was not cretaceous, as Morton and Conrad had supposed, nor eocene, as Lyell had considered it, but was of the age of the terrain nummulitique of Biaritz.

which constitute the chief part in bulk, of considerable masses of limestone in certain districts. Having obtained many specimens both from Alabama and from Vicksburg in Mississippi, in which the structure of this fossil was beautifully preserved, I first showed them to Prof. E. Forbes, who at once pronounced them not to be Nummulites, but related to some living plants or zoophytes which Mr. Jukes had brought from Australia. Mr. Lonsdale, who examined them immediately afterwards, said, "They are certainly not Nummulites, but allied to some of the bodies usually termed Orbitolites, and are I believe corals in the usual acceptation of that word." Afterwards Mr. Forbes having compared the American fossil with the living species from Australia and satisfied himself of its near affinity, sent me the following note, dated June 14th, 1847. "On the so-called 'Nummulites Mantelli.' The American Nummulites Mantelli, judging from Mr. Lyell's specimen, is not a Nummulite nor is it a foraminiferous shell. It is a species of Orbitolites and consequently a zoophyte, (probably Ascidian.) The genus Orbitolites was established by Lamarck for the reception of a fossil of the Paris basin, the Orbitolites complanata, which may be regarded as the type. Other tertiary species and a Maestricht fossil, were associated by Lamarck in the same genus, in which he also placed the 'Orbitolites marginalis' of the European seas. Respecting the true position of the last-named body, however, there is considerable doubt."

The Orbitolites complanata is very nearly allied to the American fossil. The Orbitolites elliptica of Michelin, from near Nice, and that author's Orbitolites Pratti, are also closely allied species.

In British strata, species of Orbitolites are recorded from the greensand of Milber down, from the chalk of Lewes, and from the coralline crag of Sutton. It is possible however that bodies belonging to distinct genera have been placed together in our lists.

Mr. Jukes has collected at Swan river, in Australia, numerous disciform bodies, apparently Ascidian zoophytes, which occur there in great numbers upon marine plants resembling Zostera, and when dead are found in great abundance in mud, procured by the dredge from various depths under seventeen fathoms. These disks are usually about half an inch in diameter and are composed of minute cells. They appear to me to belong to the same generic group with the tertiary Orbitolites, and such appears also to have been the opinion of Defrance, for we can scarcely doubt that these are the bodies alluded to by him (in the following passage) as living in the seas of New Holland: "Cette espece" (i. e. Orbitolites complanata of the Paris basin) "a les plus grands rapports avec celle que l'on trouve vivant dans les mers de la Nouvelle Hollande."* Marginopora of Quoy and Gaimard seems to be a similar body.

*Dict. des. Sc. Nat., p. 36, Art. Orbitolites.