Prince Patrick's Island, tell the same story of the former exist ence of something like a subtropical climate at places at present well within the arctic circle. To use the words of the Rev. Samuel Haughton,* in describing the fossils collected by Sir F. L. McClintock, "The discov ery of such fossils in situ, in 76° N. latitude, is calculated to throw considerable doubt upon the theories of climate, which would account for all past changes of temperature by changes in the relative position of land and water on the earth's surface;" and I think that all geologists will agree with this remark, and feel that if the possibility of a change in the position of the axis of rotation of the crust of the earth were once admitted, it would smooth over many difficulties they now encounter. That some such change is indeed taking place at the present moment may not unreasonably be inferred from the observations of the Astronomer Royal, who, in his Report to the Board of Visitors for 1861, makes use of the following language, though "only for the sake of embodying his description of the observed facts," as he refers the discrepancies noticed to "some peculiarity of the instrument. . . . . The transit circle and collimators still present those appearances of agreement between themselves and of change with respect to the stars which seem explicable only on one of two suppositions-that the ground itself shifts with respect to the general earth, or that the axis of rotation changes its position." ART. XXVIII.-On Fluorescence; by J. ENEU LOUGHLIN, Philadelphia. IN the year 1845, Sir J. Herschel published two papers in the 'Philosophical Transactions,' on what he termed the epipolic dispersion of light. His researches were made upon sulphate of quinia and other organic substances, from which researches he deduced the conclusion that the colors came from the surface of the liquid at which the light entered, and that a ray of light having once passed through such a stratum has lost the power of reproducing the same effect. Sir D. Brewster, in 1846, in a paper read before the Royal Society of Edinburgh, drew attention to a similar phenomenon in a solution of the green principle of leaves, and disproved the ideas of Sir J. Herschel, by show. ing that the light was dispersed not merely at the surface, but for a long distance within the fluid. In 1852, the subject was taken up by Mr. Stokes of Cambridge, and by him ably discussed. He examined many organic substances and arrived at * Journal of the Royal Dublin Society, vol. i, p. 244. several valuable conclusions. He was the first to examine the fluorescent nature of glass colored by oxyd of uranium. In June of the present year, I commenced a series of experi ments upon the tinctures and infusions of the leaves, barks, and roots of various plants. A beam of sunlight was the agent employed for illumination. The apparatus, that of Prof. Stokes. Of the specimens examined, those worthy of note, with their results, are given in the following table: The tinctures were then deprived of color by being filtered through animal charcoal, the object being to remove the coloring matter, as several of them gave reactions which were due to the presence of chlorophyll. Ön an examination they gave the following results: Tinct. of Nux vomica deserves more than passing notice; when deprived of color it gave a faint green tint in place of the original yellow tint. All the alkaloids of the above that could be obtained were examined, viz: The next step was the examination of the fluorescence shown on the pouring of infusions of different substances into water contained in a tall jar, also the fluorescence shown by paper saturated with different infusions. The flame of burning sulphur served as the illuminating agent. The intensity of color varied as is shown in the table. For the light of sulphur was then substituted that of the fol lowing illuminating agents, alcohol flame colored by different substances being used, with the accompanying results. Red by nitrate of strontia, no action. very distinct. no action. The infusions of the above were spread upon paper and made to receive the solar spectrum. Those that produced elongation of the violet portion were very decided. Esculin, very decided. very distinct. Philadelphia, Dec. 8th, 1866. .* ART. XXIX.-Note on Dr. Andrews' paper on the Glacial Drift; by E. W. HILGARD, Prof. of Chemistry, University of Mississippi. DR. ANDREWS' interesting paper on the Drift of Illinois, in the January number of this Journal, defines in a precise manner a point which I have heretofore failed to find distinctly elucidated, viz: the exact stratigraphical relations of the great stratified deposits of sand and gravel in the Northwest to such as exhibit unquestionable evidences of glacier action, and not only those which, so far as their character was concerned, might equally as well be referred to that of stranded floes, or shore-ice. It seemed strange, indeed, that the former should be absent, where so much of glacial transporting agency was apparent. The occurrence of glacier-scored rocks is likely, in general, to be confined to a moderate distance from the parent glacier. Apart from the terminal moraine, we find them frozen into the bottom or sides of the glacier, and of course into the corresponding surfaces of the iceberg detached from it. They are therefore liberated by thawing long before those unscored an *This Jour., Jan. 1867, p. 75. gular blocks, which, by falling into crevasses, become enclosed in the mass of the glacier without penetrating to the bottom. It is only when two thick glaciers unite into one at a very acute angle, that scored rocks may become imbedded in the interior of the combined mass, and afterward be conveyed to considerable distances in an iceberg. Stratification, therefore, must always be the criterion between the moraine and the deposits formed of the ballast dropped by floating ice, though, from the mode of formation, distinct or continuous stratification could not be expected even in the latter. Dr. Andrews specially mentions the stratification of the drift penetrated in the Chicago tunnel, and that by great care it can be observed in the greater part of the formation. The latter is therefore clearly not of the moraine character-it is the result of the combined action of water and floating ice, as required by the hypothesis advanced in the paper referred to by him. Nor does the occurrence of the true " glacial drift" beneath the stratified beds in any way detract from the importance of the latter, and the necessity of assigning the origin of their "thick masses to a cause more powerful in degree and more widely active, than is implied in the sentence quoted from Dana's Manual. While angular blocks do occur in the stratified drift of middle Illinois and Missouri, they, nevertheless, manifestly decrease in proportion to those of rounded form, as we advance southward; and the lithological composition of the "Orange Sand" of the Southwest is precisely such as we should expect to result from the modification, in proportion to distance and lower latitude, of the agencies to which the stratified drift of the Northwest seems to owe its conformation. University of Mississippi, Feb. 2, 1867. ART. XXX.-On Naphtha and Illuminating Oil from Heavy California Tar (Maltha); by B. SILLIMAN. HAVING lately had an opportunity to examine a specimen of "surface oil," so called, from Santa Barbara county, in California, I present the following experimental results in the hope that they may not be without interest, as an addition to our knowledge of one extreme of that class of hydrocarbons which occur in nature in the fluid form, and of every density, from those which are but little lighter than water down to the lightest naphtha found in a natural state. It is proper to state that the chemical examination of this. sample had chiefly a technical object, to prove whether or not illuminating oil of good quality could be obtained from the dis tillation of so dense a body. The experiments were conducted on quantities of from five to ten gallons each. The crude oil was very dark, almost black, transmitting yellow brown light in thin films. At ordinary temperatures (60° F.) it is a thick, viscid liquid, resembling coal tar, but with only a very slight odor. Its density at 60° F. is 0.980 or 13° Baumé. It retains, mechanically entangled, a considerable quantity of water, which is neutral in its reaction. The odor of sulphydric acid, which is very decided in this product, as I have noted in its locality, had entirely disappeared in the specimen under consideration. The tar froths at the commencement of distillation, from escape of watery vapor. It yields by a primary distillation no product. having a less density than 0.844, or 37° B. at 52° F. Distillation to dryness produced in two trials an average result as follows: Oil having a density of 890 to 0.900, 69.82 30.18 100.00 In one of these trials the product was divided as follows: Oil, of density 29° B. at 52° (885 sp. gr.), 66 Coke, water, loss, &c., 66 50.0 17.5 32.5 100.0 The coke is very large in quantity, strong, and is a good fuel, resembling gas-house coke. The odor of ammonia is given off toward the close of the distillation. It is well known to distillers of petroleum that by the process called "cracking," heavy oils unfit for illumination are broken up into bodies of less density, from light naphtha to the heavier illuminating and lubricating oils. This process is simply the application of a carefully regulated heat producing a slow distillation. By this treatment the molecules apparently rearrange themselves into groups of different density, which by a subsequent distillation are divided into fractions (or "heaps" as Mr. Warren calls them) of tolerably constant boiling points. The first distillate, having a density of about 890 at 60° F., treated in this manner, yielded a product having a density of about 885 at 60°, or only 1° Baumé lower than before distillation. After treatment with sulphuric acid and soda and redistilling from soda, it had a density of 880 at 60° F. Upon redistilling, 100 measures of this last distillate yielded— Light oil having a density of about '834 at 60° F., 21.58 Heavy" |