MISCELLANY.
SCIENCE.
Important Geological Discovery.—Sir Charles Lyell, in his address to the British Association a few months ago, mentioned the discovery of a fossil animal much more ancient than any previously supposed to exist. Heretofore, as is well known, an immense series of rocks below the silurians have been termed azoic, as exhibiting no remains of animal life; but this term must now be dismissed.
It is well known that a staff of competent geologists, under the direction of Sir William E. Logan, have been engaged for some years in a geological survey of Canada. The oldest rocks in that country are granite, described as upper and lower Laurentian, their thickness being 40,000 feet, with bands of limestone intervening. In one of these bands in the lower series of rocks, which are the most ancient, there were discovered, in 1858, certain flattish rounded masses, which seemed to be of organic origin. These were examined under the microscope by Dr. Dawson of Montreal, who, from their structure, declared them to be foraminifera, similar in character, but by no means in size, to the foraminifera living at the present day in vast multitudes at the bottom of the sea; and to this newly-discovered and wonder-exciting creature he gave the significant name Eozoon Canadense, or the Dawn-animal of Canada.
The foraminifer of the present day is a microscopic creature; the eozoon was enormous in comparison, about twelve inches diameter, and from four to six inches in thickness, presenting the general form of a much flattened globe. Its growth was by the process technically known as gemmation, or the continued development of cells upon the surface; hence, these cells form successive layers of chambers, separated by exceedingly thin walls or laminae of calcareous matter. They are now all filled with solid matter, mineral silicates, serpentine, and others; but sections or slices cut from the mass, and examined, show the form of the cells still perfect, and what is more remarkable, the very minute tubes (tubuli) by which communication was maintained from one to the other throughout the entire animal. Mr. Sterry Hunt, the chemist employed on the Canadian survey, is of opinion that the silicates and solid matters were directly deposited in waters in the midst of which the eozoon was still growing, or had only recently perished, and that these solid matters penetrated, enclosed, and preserved the structure of the animals precisely as carbonate of lime might have done. Here, then, we have an example of fossilization, accomplished by reactions going on at the earth's surface, not by slow metamorphism in deeply-buried sediments.
Papers on this subject and one by Sir W. Logan himself—have been read before the Geological Society, and will shortly be published; and at a recent meeting of the Royal Society, a highly, interesting communication in further elucidation of the matter was made by Dr. Carpenter, who has devoted himself for some years to the study of foraminifera. He confirms Dr. Dawson's general conclusions, and identifies among living foraminifera the species which has most affinity with this very ancient dawn-animal. He makes out the identification in an ingenious way, resting his proof on the peculiar structure of the cell-walls, and of the minute tubuli by which, as before observed, communication between the cells was maintained. Henceforth, we shall have to regard the silurian fossils as modern.
Since this discovery was made public, it has been ascertained that there are fossil remains of the eozoon in the serpentine rocks of Great Britain. The importance of this of course depends on the age of serpentine, and that is a question which geologists have not yet settled; but some of them are of opinion that the British serpentines are of the same age as the Laurentian rocks in which the Canadian eozoon was found. Pending their decision of the question, keen explorers are on the search for other specimens.
Curious and Delicate Experiments.—Dr. Bence Jones recently communicated to the Royal Society of Great Britain the result of a series of experiments by [{281}] which he had attempted to ascertain the time required for certain crystallized substances to reach the textures of the body after being taken into the stomach. In other words, he proposed to solve these problems: If a dose of medicine be given, what becomes of it, and does it arrive quickly or slowly at the parts for which it is intended? It is obvious, that if these questions could be accurately determined, medical men would have a better knowledge than at present of the action and progress, so to speak, of medicine within the body. Substances, when taken into the stomach, pass into the blood, which may be supposed to distribute them to all parts of the body. If, in ordinary circumstances, no trace of a particular substance can be found in a body, but is found after doses of the substance have been administered, it is clear that the doses are the source from which that trace is derived.
Lithium is a substance sometimes given as medicine. Dr. Jones gave half a grain of chloride of lithium to a guinea-pig, on three successive days; and, by means of the spectrum analysis, he found lithium in every tissue of the animal's body, even in the cartilages, the cornea, and the crystalline lens of the eye. In another experiment, the lithium was found in the eye eight hours after the dose had been administered; and in another, four hours after. In another, the lithium was found after thirty-two minutes, in the cartilage of the hip, and in the outer part of the eye. These cases show that chemical substances do find their way very quickly into the tissues of the body; and a similar result appears from experiments on the human subject. A patient, dying of diseased heart, took fifteen grains of nitrate of lithia thirty-six hours before death, and a similar quantity six hours before death. Lithium was afterward found distinctly in the cartilage of one of the joints, and faintly in the eye and the blood. A like result was obtained with a patient who had taken ten grains of carbonate of lithia five and a half hours before death. And to this Dr. Bence Jones adds, that he expects to find lithium in the lens of the eye after operation for cataract.
Giant Trees of California.—Some time ago, much regret was expressed that the giant trees (Wellingtonia) of California had been recklessly cut down. Their fall was a loss to the world. But Sir William Hooker has received a letter in which Professor Brewer, of the California State Geological Survey, reports that "an interesting discovery has been made this year of the existence of the big trees in great abundance on the western flanks of the Sierra Nevada. They abound along a belt at 5,000-7,000 feet of altitude for a distance of more than twenty-five miles, sometimes in groves, at others scattered through the forest in great numbers. You can have no idea of the grandeur they impart to the scenery, where at times a hundred trees are in sight at once, over fifteen feet in diameter, their rich foliage contrasting so finely with their bright cinnamon-colored bark. The largest I saw was 106 feet in circumference at four feet from the ground, and 276 feet high.