The decomposition of chlorate of potash in the presence of oxides of manganese and copper has been studied by M. Wiederhold. He found that, contrary to M. Schönbein's hypothesis, oxygenated bodies are not the only ones capable of determining the decomposition, for that spongy platinum had the same power. A rise of temperature was found to take place in the mixture as soon as the bath in which the retort was placed had reached a temperature of 250° for the mixture of chlorate and peroxide of manganese, and 290° for the mixture with oxide of copper. Oxygen began to be given off at temperatures varying from 200° to 285°, according to the mixture employed.

M. St. Clair Deville has made some interesting discoveries connected with the decomposition of bodies by heat. On passing a current of hydrogen through a porous earthen tube, it diffuses so rapidly that the gas which issues from the other end of the tube will be found to be not hydrogen but air. If the porous tube is surrounded by a larger and shorter tube of glazed porcelain into which carbonic acid is passed at one end, the two gases will be found to have changed places by the time they reach the other end of the two tubes.

When these tubes are heated to a temperature of 1,100° to 1,300° C., and a current of steam passed through the inner one, while a carbonic acid is passed through the outer tube, the gas collected consists of hydrogen and oxygen, mixed with carbonic acid.

M. Deville considers the decomposition of a substance to be in all respects analogous to the ebullition of a liquid; water is completely decomposed at a temperature sufficient to expand the vapour to tenfold its volume at 0° C. The decomposition can also take place at lower temperatures, the phenomenon being in this respect analogous to that of the evaporation of liquids below their boiling points. M. Deville has also extended his observations to the dissociation of carbonic acid by means of heat.

PR

GEOLOGY AND PALEONTOLOGY.

ROFESSOR RAMSAY has discussed the significance of the physical breaks and changes of life in the several strata of the Paleozoic system. When he finds that strata have been upheaved, denuded, and had other rocks deposited upon them, he concludes that we here have evidence of an extremely long interval of time unrepresented by any deposit, the vast duration of which may be computed by noticing that the physical break is always accompanied by a change in the life; hence, also, he supposes that a change in the life probably indicates a physical break. From the Lauvention rocks to the top of the Silurians are six of these cases of nonconformity; in the Old Red Sandstone, two; in the Carboniferous strata, one; and one between the Carboniferous and Peruvian ; ten in all. Now, in no one of these strata is the duration so long that from bottom to the top all the species change; yet in the breaks one commonly finds that not only have the species but most of the genera disappeared,

and been replaced by new forms. The Professor therefore concludes that the Paleozoic time, of which we have no record, must be regarded as far longer than that represented by the whole series of known Paleozoic rocks.

Mr. Carter has described the skull of a Bos primigenius, from the peat of Reach, in Cambridgeshire, offering more satisfactory evidence than anything hitherto known of the co-existence in England of man with the supposed ancestor of our domestic cattle. The skull was found beneath 7 feet of peat, and with it most of the skeleton, though there were few limb bones, and not many ribs. It was brought to Cambridge, still much covered with peat, and sold. The investing matter was duly removed, and then became visible a chipped stone celt driven far into the skull, and broken off level with the frontal bone. The fracture was old, the flint was old, the bone around it was depressed, and the weapon, which passed obliquely through the sphenoid into the orbit, penetrating the brain-cavity for three inches, was firmly wedged in the skull. The flint appeared to have been one of those elongated narrow forms with sub-parallel sides which are supposed to have been unknown in the earlier Stone age. It was conjectured that the tool had been lashed to a pole, and so used, when the ox was running, to deliver the blow which, from being accidentally oblique, has from its violence snapped the celt. Mr. Carter did not regard the specimen as bearing on the antiquity of our species, and thought it rather an evidence that the beast lived to very modern times than that man was an ancient denizen of the land. This is an echo of the idea broached by Mr. Prestwich on the chipped flints from the gravel, and cannot be received with too great caution, for the facts of the case are these:

Here in the peat of the Bedford Level are found Bos primigenius, Bos frontosus, Cervus Hibernicus, and Bos longifrons, all of which are extinct ; the last species going for little, since it frequently occurs in Roman graves. The existing species are not animals now common in the country, and must all be regarded as becoming extinct; among them are the brown bear, the wolf, otter, beaver, wild hog, roebuck, red deer, &c., altogether not more than twelve. Now, when one-fourth of a fauna has died out, and the remainder, even though for obvious reasons, disappeared, it cannot but be supposed that the change indicates a remote antiquity for the stratum in which their remains are entombed. Had the skull been an ordinary one, unassociated with human work, beyond question this antiquity would never have been doubted; and, therefore, the legitimate conclusion from a specimen like this seems to be, that in the days of the Irish Elk, beef was already the food of a Briton, courageous and skilful enough to hunt and slaughter the most formidable beast of his time.

Professor Harkness has written elaborately on the Skiddaw slates, tracing their features through the Lake district. He estimates their average thickness in the North of England at 7,000 feet. The mineral character varies so much from place to place as to be worthless for division of the deposit into subordinate groups. From both fossil and physical features the Professor regards the Skiddaw slates as of Llandeill age. These strata appear to be the metropolis of the graptolites, and yield to

the collector a number of new radiating and branching forms, which are referred to the genera Phyllograptus, Tetragrapsus, Dichograpsus, &c.

Professor Rupert Jones publishes a monograph of the Estheria, crustaceous creatures with a carapace in two pieces, so like bivalve shells that they have been referred to as such by the best authorities. The living forms all inhabit ponds and fresh water, being rarely found in marshes or near the sea. There are fourteen fossil species, ranging from the Old Red Sandstone to the most recent strata. The existing forms being all fresh water, it is thought likely that the same distribution held good for the fossils, and hence that they offer strong suggestive evidence that the fishes of the Old Red Sandstone, like their existing allies, had fresh water habits.

The Rev. O. Fisher has described a bed of peat near Colchester which contains the bones of Elephas primigenius. It rests on stratified gravel and is overlaid by brick-earth. This peat contains the remains of insects differing from British existing species, and from their brilliant colours, &c., are thought to have their nearest affinities with those of tropical countries. Mr. Fergusson has chronicled the recent changes in the Delta of the Ganges. In early historical times, the plains of Bengal were drained by the Brahmapootra passing to the sea by Goalparah, and the Ganges which, passing Rajmahal, ran parallel to it. Then came the upheaval of the Modopore jungle, north of Dacca, producing a depression known as the Sylhet Jheels, into which the Brahmapootra was diverted by the upheaval. The Jheels were gradually filled up, and in the beginning of this century the river returned to its former bed. The result of this was that all the rivers of the western half of the Delta were re-opened, and should the present drainage continue, the two great rivers promise to resume very nearly the courses held before the disturbance. He thinks there is sufficient historical evidence to demonstrate that 5,000 years ago the fruitful rice plains of Bengal were a jungly swamp, with only a few spots on the larger rivers which were inhabitable and capable of cultivation.

MEDICINE, SURGERY, THERAPEUTICS.

MEDICINE.

Diseases of the Liver. Two very important works on the diseases of the liver have very recently been added to the medical literature of the country; they both contain some new and really scientific observations, based upon studies in physiological chemistry, and are calculated to be of service to the medical profession. One work is the "Clinical Treatise on Diseases of the Liver," by Dr. Freid. Theod. Frerichs, translated by Dr. Murchison for the New Sydenham Society. The other work is entitled "Jaundice its Pathology and Treatment," by Dr. George Harley, of University College.

It may not be amiss to inform our non-professional readers, that since 1853 it has been known that the liver performs another function

besides that of secreting the bile. This organ is also concerned in the formation of a sugar, an amyloid or a starchy principle, the true conditions and pathological relations connected with which are not at present fully known; but it is not discharged like bile into the intestines,—it is taken up by the veins in the liver, conveyed into the general circulation, and becomes subservient to the processes of respiration and nutrition. The liver has therefore two distinct functions, the formation of bile and that of sugar. The latter is called the glycogenic function.

The works of these two authors may be said to represent the latest news on the pathology of certain forms of jaundice; the true theory and explanation of which is yet by no means ascertained. Without attempting to go into a review of these works, we simply recommend them to the favourable notice of the public and to the medical profession as the best standard scientific and practical treatises on liver diseases. The treatment of jaundice and its diagnosis in the work of Dr. Harley shows the great advantages that physiological chemistry offers to explain difficulties, and guide the practitioner in his views of treatment.

The Laryngoscope.-The application of this new instrument (referred to in "Popular Science Review," page 281), invented for examining diseases of the vocal organs, is becoming daily more popular and better known.

Dr. George Johnson read a paper upon the laryngoscope before the London Medical Society in April; Dr. George Gibb lectured before the élite of the musical world, at the Musical Society of London; and Dr. Sieveking read a paper before the members of the Harveian Society, each illustrating his discourse by cases and observations. Professor Czermak, the inventor, who is now visiting this country (June 9), gave a clinical demonstration last week at University College Hospital.

The detection of obscure or unsuspected disease is a fact of great value in the diagnosis and treatment, which in the hands of skilful men will reward their labour in this field of research.

Resuscitation and Restoration (of Suspended Animation) from Drowning.— The last volume (xlv.) of the "Medico-Chirurgical Transactions," contains the report of the committee appointed to investigate the subject of suspended animation.* A large number of experiments upon animals, and on the dead body, the result of which are of such importance as to deserve a notice, tend to modify the previously adopted plans for the restoration of persons asphyxiated from drowning.

The method of Dr. Marshall Hall, usually called the postural or ready method, consists essentially "in turning the body round gently on one side, and a little beyond, and then briskly on the face, alternately," making pressure along the back of the chest each time the body is brought into the prone position. Up to the present time this is generally considered the best plan that could be adopted to expel and introduce air into the respiratory cavities or lungs, but no definite information was given as the result of

The members of this committee were: C. J. B. Williams, M.D., F.R.S.; C. E. Brown-Sequard, M.D., F.R.S.; George Harley, M.D.; W. S. Kirkes, M.D.; Hyde Salter, M.D., F.R.S.; J. B. Sanderson, M.D.; W. S. Savory, F.R.S.; E. H. Sieveking, M.D.

observation and experiments. The committee has undertaken to do this in a very elaborate series of experiments on the dead subject, and it has now fully determined the best method of introducing air into the lungs. The method of restoring the action of the lungs in cases of drowning, introduced last year by Dr. Silvester, may now be considered to be satisfactorily proved to be the best known.

The volume of air inspired, as found upon actual measurement, in Dr. M. Hall's plan "to imitate respiration," varied much, from a few cubic inches to 8 or 10 inches, but never exceeding 15 cubic inches. In Dr. Silvester's plan it was found, on extending the arms upwards, a volume of air was inspired into the chest which varied from 9 to 44 cubic inches, and by bringing down the patient's arms gently, and firmly pressing them against the sides of the chest, so as to diminish the cavity of the thorax, and by alternating these movements, a regular exchange of air was produced, the quantity of which in several instances exceeded 30 cubic inches, and in one instance amounted to 50 cubic inches.

The committee recommends that the plan of Dr. Silvester should be employed in the following manner :—

The body laid on its back (on a flat surface, or a plane slightly inclined from the feet upwards), a firm cushion placed under the shoulders, the head kept in a line with the trunk. The tongue should be drawn forward so as to project a little from the side of the mouth; then the arms should be drawn upwards, until they nearly meet above the head, the operator grasping them just above the elbows, and then at once lowered and replaced at the side. This should be immediately followed by moderate pressure, with both hands, upon the lower part of the sternum. This process is to be repeated about twelve or fourteen times in the minute. As regards facility of application, the plan recommended by Dr. Silvester is equally or perhaps more effective than the Marshall Hall plan.

OPHTHALMIC SURGERY.

Atropine Paper.-Mr. Streatfield has just introduced a portable and convenient substitute for the solution of atropine in ordinary use. He has used green tissue-paper which has been steeped and dried with the solution of atropine, so that one-fifth of a square inch contains enough atropine to dilate the pupil. The small piece of paper is wetted and placed under the lower eyelid, where it causes no pain or inconvenience for the short time required to dilate the pupil. In many cases this small scrap of paper has been found to cause less irritation than the drops of the solution of sulphate of atropine in general use.

The Ophthalmoscope.-A binocular ophthalmoscope has been invented by Mr. Carter, formerly of the Kent County Ophthalmic Hospital. The "Ophthalmoscopic Atlas" of Liebreich is a valuable addition to ophthalmic surgery; it contains twelve well-executed plates, indicating the most interesting appearances in those parts of the eye which have hitherto been recognized by the best observers in the new science of ophthalmoscopy.

The Calabar Bean.-During the last few weeks observations have been going on in some of the London and provincial hospitals to test the properties of the Calabar or ordeal bean in ophthalmic surgery.