4. Report on the exploration of the Country between Lake Superior and Red River Settlement and between the latter place and Assiniboine and Saskatchewan. By S. J. DAWSON, Esq., C.E. Printed by Order of the Legislative Assembly. Toronto, 1859.

A particular account of these expeditions was given in the last number of this Journal, p. 218.

5. Geological Survey of Canada. Report of Progress for the year 1858. Montreal, 1859.

6. Map of the Northwest part of Canada, Indian Territories and Hudson's Bay; compiled and drawn by THos. DIVINE, Provincial Land Surveyor and Draftsman, by order of Hon. Jos. CAUCHON, Commissioner of Crown Lands, Toronto, March, 1857. Published by S. Derbeshire and G. Desbarats.

This is a map in outline, geologically colored, of the region above mentioned, extending as far north as 75° north latitude and as far south as 45° north latitude. Being made previous to the recent exploring expeditions it is now behind our present knowledge. The authorities on which it is based are J. Arrowsmith, A. Mackenzie, D. Thompson, the Admiralty and Coast Survey Charts, Pacific Rail Road Survey Reports. Sir Geo. Simpson, Governor of the Hudson's Bay Company, Sir Wm. Logan and others are also quoted. The isothermal lines are given according to Dove and Blodget.

7. Government Map of Canada from Red River to the Gulf of St. Lawrence, compiled by THOMAS DEVINE, Head of Surveys, Upper Canada Branch, Crown Land Department. November, 1859.

This map in three sheets, is limited to Upper and Lower Canada, the counties of which are distinctly indicated by color, and the more detailed topography is also clearly given. It is clearly drawn, and presents in its margin a variety of useful information respecting the resources of Canada.

DR. BARTH IN ASIA MINOR.-Dr. Henry Barth, the celebrated traveller in Africa, has published in a Supplement to Petermann's Mittheilungen an account of a journey which he made in 1857-1858 from Trapezund, through the interior of Asia Minor, by way of Tokat, Amássia, Yûsgad, Cesarea and Angora to Constantinople. His attention was directed to the physical structure of the country and also to the remains of ancient art. The archaeological inquiries which he made will hereafter be made public, in detail,-though many of the more important facts are brought out in Petermann with illustrative wood cuts. A sketch of his journey is given on an accompanying chart with plans of Tókat, Amássia, Kara-hissár and Kyr-schehr.

D. C. G.

ART. XXXVII.-Further Remarks on Numerical Relations between Equivalents; by M. CAREY LEA.

IN papers on this subject published in the January and May numbers of this Journal for the present year, I endeavored to show that a large number of so-called elements could be arranged in seriated groups, the members in each series differing from each other by a common quantity, in most cases the number 44 or one approximating to it. I endeavored to show that not only were these groups natural groups, but that the chemical properties of the members of each group corresponded in many cases with their position in it. These observations seemed to favor the view at present gradually gaining ground, that those bodies which we have as yet failed to decompose, we have not proved to be elementary.

An interesting and elaborate paper by Gustav Tschermak, published in the Proceedings of the Academy of Science of Vienna, and extracted in an abridged form in Knop's Centralblatt, (July 4, 1860,) on the subject of the law of volumes of liquid chemical compounds affords a support to the views above expressed, from a new source. The author therein shows that many of the substances usually classed as elements comport themselves in the physical properties exhibited by their combinations as compound bodies, and that it is possible from these physical properties to determine (hypothetically) the number of "physical" or absolute atoms which he supposes to be contained in a chemical atom of such body or pseudo-element. He endeavors to show that it is possible to calculate the specific gravity of a liquid from its atomic weight and the number of simple (chemical) atoms in its compound molecule, as data, but that the results lead to the immediate inference that each chemical atom contains with few exceptions several physical atoms.

For particulars of his theory I must refer to the original paper, but some of his results are as follows:

These numbers are taken from the table of mean numbers, p. 508 of Centralblatt and are those subsequently used by the author for determining the "physical

If now we arrange the first six of these substances in parallel series we shall find

Thus a common difference in each case amounting to 16-17 corresponds with a difference of two of the physical atoms into which Tschermak divides the chemical atoms.

If now we put O=20, Cl=2cl, P=2p, the approximate difference between S and O, Cl and F, &c., (16-17)=2A', the difference (48) between S and Se=A" and the difference (44–45) between the terms of the nitrogen series =▲, we can express the whole of three important series in terms of these six quantities, so that at one and the same time both the numerical value of the atomic weights and the number of Tschermak's physical atoms shall be correctly expressed.

In which table the number of radicals by which the chemical atom of each body is expressed, corresponds with the number of Tschermak's physical atoms, while their numerical value is equal to the atomic weight of the body.

Thus tellurium o, A',A", would have two each of three radicals, in all six, agreeing with the number of physical atoms as

signed to it, while their value 2×8+2×8+2×48=128, at. wt. of tellurium.

These observations of Tschermak, taken in connection with the numerical relations which exist between atomic weights, give rise to very interesting results, and if the conclusions which he arrives at from his experiments should be confirmed, they cannot fail to exercise a very important influence on the progress of chemical science.

Philadelphia, August 28th, 1860.

ART. XXXVIII.-On the Production of Ethylamine by Reactions of the Oxy-Ethers; by M. CAREY LEA.

[Read before the Am. Assoc. for the Adv. of Sci. at Newport, August, 1860.] WHILE engaged in making a series of experiments on this subject I met with the paper of Juncadella* and the observations of De Clermontt on the same subject. Finding that the subject had less novelty than I supposed I merely offer here one or two of the results which I have obtained.

Nitrate of ethyl C,H,O, NO, heated in sealed tubes with chlorid of mercurammonium HN CI for many hours in the Hg(

3

water bath did not appear to react upon it. Kept for some time in a boiling saturated solution of chlorid of calcium the tubes although extremely thick green glass-combustion-tube of small calibre was used, exploded with great violence, shattering the vessel in which they were contained, although they had been wrapped in strong cloth.

Nitrate of ethyl heated in a sealed tube with chlorid of zincH,

ammonium ZNCI in the water bath, does not appear to act upon it.

Zn

Nitrate of ethyl heated in the water bath in a sealed tube with carbamate of ammonia NH, O, NH, C, O, dissolves the salt. On cooling radiated crystals form. The contents of the tube evaporated to dryness with excess of chlorhydric acid, and then exhausted with ether to which a few drops of strong alcohol have been added, yielded a solution which gave a chamois colored precipitate with bichlorid of platinum, consisting of chloroplatinate of ethylamine.

1185 gm. substance gave 0465 metallic platinum corresponding to 39-25 per cent; theory requires 39-29

The product was but small. Probably portions remained undissolved by the ether. No doubt portions of di- and triethylamine are also formed in the above reaction, in the same manner as in those of the halogen ethers with ammonia.

Philadelphia, July 11, 1860.

* Rép de Chimie pure, Tome 1, 273.

† Ibid., 274.

AM. JOUR. SCI.-SECOND SERIES, VOL. XXX, No. 90.-NOV., 1860.

ART. XXXIX.-On the Optical Properties of the Picrate of Manganese; by M. CAREY LEA, Philadelphia.

[Read before the Am. Assoc. for the Adv. of Sci. at Newport, August, 1860.] BREWSTER and HAIDINGER have described a remarkable property possessed by certain crystalline surfaces, of reflecting, besides the ray normally polarized in the plane of incidence and reflection, another ray, polarized perpendicularly to that plane, and differing from the former in being colored, a property rendered more conspicuous by the fact that the color of the ray SO polarized abnormally is either complementary to, or at least quite distinct from the color of the crystal itself.

I find that this property is possessed to a remarkable degree by the picrate of manganese. This salt crystallizes in large and beautiful transparent right rhombic prisms, sometimes amberyellow, sometimes aurora-red, exhibiting generally the combination of principal prism, and macrodiagonal, brachydiagonal and principal end planes. In describing this substance in a paper on picric acid and the picrates,* I mentioned that in a great number of specimens examined, no planes except those parallel with or perpendicular to the principal axis had been met with. Since then I have obtained in several crystallizations specimens exhibiting a brachydiagonal doma, but this appears to be rather unusual.

The optical properties of this salt are very interesting. It exhibits a beautiful dichroism. If the crystal be viewed by light transmitted in the direction of its principal axis, it appears of a pale straw color, in any other direction, rich aurora-red in some specimens, in others salmon color. A doubly refracting achromatised prism gives images of these two colors, except the light be transmitted along the principal axis of the crystal of picrate, in which case both are pale straw color.

But it also possesses in a high degree the property of reflecting two oppositely polarized beams, and the great size of the crystals in which it may readily be obtained, renders it peculiarly fitted for optical examination. If one of these crystals be viewed by reflected light while it is held with its principal axis lying in the plane of incidence and reflection, the reflected light is found to be not pure white, but to have a purple shade. Examined with a rhombohedron or an achromatised prism of Iceland spar, having its principal axis in the plane of incidence and reflection, the ordinary image is white as usual, while the extraordinary is of a fine purple color, the phemenon having the greatest distinctness when the light is incident at the angle of maximum polarization.

*This Journal, Nov., 1858,