may be employed within certain limits without materially impairing the tenacity of the metal. In a letter to the Editors, dated Nashville, June 9th, 1860, Dr. Wood says:

"One point in particular that strikes me as being worthy of note is the remarkable degree in which Cadmium possesses the property of promoting fusibility in these combinations. The alloy of one to two parts cadmium, two parts lead, and four parts tin is considerably more fusible than an alloy of one or two parts bismuth, two parts lead and four parts tin; and when the lead and tin are in larger proportion the effect is still more marked. It takes less cadmium to reduce the melting point a certain number of degrees than it requires of bismuth, besides that the former does not impair the tenacity and malleability of the alloy, but increases its hardness and general strength.

Bismuth has always held a pre-eminent rank among metals as a fluidifying agent in alloys. Its remarkable property of 'promoting fusibility' is specially noted in all our works on chemistry. But I do not find it intimated in any that cadmium ever manifests a similar property. The fact indeed appears to have been wholly overlooked-owing perhaps to the circumstance that as an alloy with certain metals cadmium does not promote fusibility.

Cadmium promotes the fusibility of some metals, as copper, tin, lead, bismuth, while it does not promote the fusibility of others, as silver, antimony, mercury, &c., (i. e., does not lower the melting point beyond the mean.) Its alloy with lead and tin in any proportion and with silver and mercury, within a certain limit, say equal parts and especially of two parts silver and one of cadmium or two parts cadmium and one mercury are used, are tenaceous and malleable, while its alloys with some malleable metals, (gold, copper, platinum, &c.,) and probably with all brittle metals are brittle.'

I notice a great discrepancy among authors as to the melting point of this metal. It is usually put down the same as that of tin, (442° F.), Brande (Dict. of Science and Arts,) says it 'fuses and volatalizes at a temperature a little below that at which tin melts.' Daniell, (according to the New American Cyclopedia,) gives its melting point at 360° F., while Overman places it at 550° and gives 600° as the temperature at which it volatalizes.

The latter is doubtless the nearest the truth. The metal requires for its fusion a temperature too high for measurement by the mercurial thermometer, but from relative tests with other metals I should place its melting point in round numbers at 600° F. as it melts and congeals nearly synchronously with lead, the melting point of which is stated by different authorities as 594°, 600°, and 612° F. It volatalizes at a somewhat higher heat.

I draw attention to these facts believing that the metal possesses properties valuable to Art and interesting to Science, and that it merits more thorough investigation than appears to have been bestowed upon it."

[We have had time only to repeat a few of Dr. Wood's interesting experiments in regard to the remarkable influence which cadmium exercises in lowering the fusible point of various alloys. The alloy made by fusing together two parts of cadmium, two parts tin, four parts lead and eight parts bismuth melts at a temperature varying not far from 70° C. (158° F.) It may appropriately be called "Wood's fusible metal.”—EDS.]

II. GEOLOGY,

1. Note from Dr. NEWBERRY, in reply to Mr. LESQUEREUX, (in a letter to the Editors).—I see by the note from Mr. Lesquereux, [contained in this Journal, xxix, 485,] that my letter from Santa Fé was unacceptable to him. This both surprises and grieves me, as the thought that he might be drawn into the controversy had not occurred to me; and I am sincerely sorry to learn that one with whom I have had so many years of friendly intercourse could so readily misconstrue both the statements and the spirit of my letter. Possibly its tone may have failed to reflect the great respect which I have had and still have for Prof. Heer; and to others than Mr. Lesquereux it may have seemed not altogether courteous. It should be borne in mind, however, that the discussion in reference to these fossil plants, and the age of the strata containing them, had already been repeatedly brought before the public; and that in this discussion the tone of the associate of Prof. Heer had been marked by a degree of arrogance difficult to bear patiently. Prof. Heer had called them Miocene-an error which with the imperfect material in his hands was natural enough; and one which should detract nothing from his high reputation-but by the testimony of several observers they had been proved Cretaceous. Ignoring their testimony, however, and adhering to his former opinion, a portion of his letter to Mr. Lesquereux was written to perpetuate what I knew to be a mistake. It also did me, as I conceive, manifest injustice. That letter reached me when I had been for months in exile, and where I was surrounded by proofs of the truth of the position I had before taken-circumstances favorable to the development of a little honest indignation. In the freshness of that feeling my reply was written, and I am willing to admit, if others think so, that it was not sufficiently respectful.

So much for the manner of my letter. In regard to its statements of fact I fear I shall be unable to make any such concession. On the contrary, my regard for truth requires that I should repeat each and all of them.

(1.) Prof. H. considered the plants in question Miocene. There is not the shadow of a doubt that they are Lower Cretaceous.

(2.) Prof. H. states that "except Credneria and Ettingshausenia all the genera enumerated (in my list) are represented in the Tertiary and not in the Cretaceous." It will be observed that he does not say they are characteristic of the Tertiary, or "of the Tertiary," as Mr. Lesquereux quotes him—but distinctly affirms that they are not represented in the Cretaceous." Hence there is no propriety in the remarks of Mr. Lesquereux on this point; and the error in the statement of Prof. Heer shown by reference to Stichler's paper, before quoted, remains unexplained. If that error was not accidental, it was designed. If accidental, as I cannot for a moment doubt, the offensive clause of my letter is no more than just. If designed, stronger language would be admissible. The appeal to "authority" has been nearly exhausted in this discussion, and the time has passed when personal influence could make errors pass for truths. Prof. Heer is a man of estimable character, of

AM. JOUR. SCI-SECOND SERIES, VOL. XXX, No. 89.-SEPT., 1860.

great learning and of world-wide reputation, and, I am sure, would be one of the last to ask us to believe a scientific statement simply because he had made it.

(3.) In my letter I made no supposition in reference to the Tertiary flora of Kentucky, Tennessee or Mississippi. I merely stated some facts in reference to the Miocence flora of the country bordering the Upper Missouri, 1000 miles distant from the nearest of these States. I also distinctly said that the absence of tropical plants from the collections made there, was only negative evidence. They may be found in that region to-morrow, but at the time of writing that letter they had not been found, and all the material in my hands indicates, as I then said, a Tertiary climate warmer than the present, but still temperate.

(4.) I was also fully aware that marine Tertiary deposits extend up the Mississippi even higher than stated by Mr. Lesquereux. I excluded them from "the central portion of the continent;" by this meaning, as I then explained, "the region between the Mississippi and the Sierra Nevada. Here, too, the evidence is negative, but now stands just as I represented it.

(5.) Mr. Lesquereux says: "I cannot admit, as Dr. Newberry appears to do, that the fossil flora of the American Cretaceous, ought to be closely related to the European." My only reference to this question will be found on page 216 (Journal, March, 1860), where I say " We may find hereafter, in other parts of the continent than those in which I have examined the Cretaceous strata, fossils which shall assimilate our flora of that period more closely to that of Europe, but, so far as at present known, our plants of this age present an ensemble quite different."

(6.) The statement made by Mr. Lesquereux that "the age of the strata from which American fossil plants have been taken is mostly uncertain," is manifestly incorrect. At least nine-tenths of the species enumerated are from the Carboniferous and Devonian rocks, whose place in the geological series is certainly well ascertained. Of those collected and not yet catalogued, perhaps an equal proportion have been obtained from the Cretaceous and Miocene strata, of which the places in the series have been as accurately determined, by the molluscous fossils which they contain.

(7.) It is true that in America fossil botany has had but few devotees, and doubtless all of them have at times keenly felt the want of more books and specimens bearing on their subjects of study. Still, I believe everything that has been published in reference to fossil plants is accessible to the American student within the limits of his own country. At the same time it is also true that a satisfactory comparison between the extinct floræ of Europe and America can only be made by means of full collections of well-marked specimens, many more than we yet possess.

Mr. Lesquereux is aware, as is every one who has given the subject any attention, that our knowledge of the flora of the different geological formations has been limited, not so much by the want of learning and acuteness in the cultivators of fossil botany, as by the small number and imperfect preservation of the fossil plants collected. It could hardly

be otherwise, then, than that in the whole New World material should be discovered which should throw new light on the ancient vegetation of the globe. The idea that no American can be qualified to make good use of such material, is another instance of the arrogance to which I have before alluded, and to which it would be unmanly tamely to submit.

III. BOTANY AND ZOOLOGY.

1. Geological and Natural History Survey of North Carolina. Part III. Botany; containing a Catalogue of the Plants of the State, with Descriptions and History of the Trees, Shrubs, and Vines. By Rev. M. A. CURTIS, D.D. Raleigh, 1860: the First part only, the Woody Plants of North Carolina. pp. 123, 8vo.-We have turned over the pages of this popular exposition with much interest, and gleaned some valuable information. "Botanists will of course find fault with it," says the author, who we well know could write scientifically and profoundly enough, if he so pleased, but who has here come down to the level of his most unlearned readers, discoursed separately of trees, shrubs, and vines, and classified these in a fashion which might well shock the susceptibilities of a stickler for technical nomenclature and natural system in botany. Now, we are not shocked at all; indeed we quite enjoy a glimpse of Flora en deshabille and slip-shod, and are well aware how much easier it is, and how much better in such cases, to fit your book to its proper readers than to fit the readers to it. The fault we should find is not with the plan of this Report, but with the quantity. We could wish for more of it, for a volume as large at least as Mr. Emerson's Report on the Trees and Shrubs of Massachusetts. We quite like to see the popular names put foremost, but would suggest that the botanist who does this should lead as well as follow the indigenous nomenclature, so far as to correct absurd or incongruous local names. and introduce right or fitting ones as far as practicable. For instance Virgin's Bower is not a proper name for Wistaria frutescens, and is rightly applied to Clematis Virginiana over the leaf. (We venture to add, in passing, C. Viorna to the list, having gathered it in Ashe County.) And, although the people along shore call Baccharis by the name of the English annual weed, Groundsel, it were better to write it Groundsel-tree. Yellow wood is the name of Cladrastis, rather than of Symplocos, which the Carolinians call Horse-Sugar. Dr. Curtis can coin a name upon occasion; for surely nobody in Carolina knows Menziesia globularis as False Heath, nor has it any scientific claim to this appellation. While in critical mood we may express a strong dissent from the proposition that Rhododendron punctatum is too inferior to the other two species "to attract or deserve much attention." With us, it is surpassingly beautiful in cultivation, none the less so because its habit is so different, having light and pendent branches, when well grown forming broad and thick masses, and loaded with its handsome rose-colored blosWhile Leucothoë Catesbai is called "a very pretty shrub," the far handsomer Andromeda floribunda, so much prized by our nurserymen, gets no commendation. Magnolia Fraseri may not only be "cultivated in the open air near Philadelphia," but is perfectly hardy near Boston, and the earliest to blossom; but we never noticed the fragrance of the flow

soms.

ers. On the other hand, as it is native as far south as Florida, it might thrive in plantations any where in North Carolina. The flowers of M. cordata are described as if larger than those of M. Fraseri, instead of the contrary; we could hardly say much for their beauty, except in comparison with those of the common Cucumber-tree. Prunus Virginiana is omitted; yet surely it is not wanting in North Carolina. And it is almost an excess of conscientiousness to leave out Cladrastis, the handsomest tree of the country, all things considered, when it is known to grow only a few rods over the Tennessee line.

On the other hand, we are disposed to doubt if the genuine White Spruce, (Abies alba,) occurs in North Carolina. At length we know this tree, but only in Canada and parts adjacent. It is more, instead of less northern in its range than A. nigra. But since President Wheeler has pretty nearly determined the existence of A. Fraseri on the Green Mountains in Vermont, we could not deny that A. alba grows with the latter on the high mountains of North Carolina. We make our little criticisms freely, as we know the excellent author would wish,-for we think it likely that this part of the Report will pass to a second edition,—when we hope it will be largely augmented.

A. G.

2. Thwaites, Enumeratio Plantarum Zeylanica, Parts I. II. 8vo, pp. 160. 1858-1859.-A complete enumeration of the known plants of Ceylon, with characters of new or little known genera and species, and numerous descriptions and critical remarks, the synonymy, &c., elaborated by Dr. Hooker. These two published parts extend from Ranunculaceœ to Composite; so that a good-sized volume will complete the work, and constitute an important adjunct to the great Indian Flora.

A. G.

3. Walpers, Annales Botanices Systematica, continued by Dr. C. MÜLLER, Berol.-Five parts of the fifth volume are published, extending to page 800, and to the order Coniferæ.

A. G.

4. Bueck, Index ad De Cand. Prodromum, etc. Pars III. Hamburg, 1859. pp. 506.—This useful Index to De Candolle's Prodromus is here continued from the second part of the seventh to the thirteenth volume. As we may expect that at no distant period the Prodromus will be termi nated, as announced, we trust that the next Index will combine the whole into one continuous alphabetical list.

A. G.

5. Synopsis Methodica Lichenum omnium hucusque cognitorum, præmissa introductione lingua Gallica tractata, scripsit WILLIAM Nylander. Fasciculus II, Parisiis ex typis L. Martinet via dicta Mignon, 2, 1860. 8vo. pp. 141-430.—We are glad to welcome another portion of the important work of Dr. Nylander, which is indispensable to every Botanical library. Beginning with the Caliciei, the present part embraces the Beomycei, the Cladonici, the Usneei, and the Parmeliei, ending with the genus Physcia. The higher tribes of Lichens are by no means the least difficult, and nothing in the part before us is more acceptable than the author's elaboration of the genus Sticta;-disposed by him in Sticta, Stictina, and Ricasolia. The last general synopsis of Lichens, that of Acharius, was published nearly fifty years ago, and the vast amount of valuable matter, scattered in many publications, which has since been accumulating, has long needed to be brought together in one work. This Dr. Nylander proposes to accomplish, adding also the results of his investigation of all the