eleventh lumbo-caudal vertebra. Posterior to this point, therefore, we have arranged around the vertebral column four great nervous cords-two of which are superior, and situated one on each side of the vertebral spines, and two inferior, and placed one on each side of the vertebral bodies below the transverse processes. They are continued back to the tail, and their chief function is to supply the four great muscles which act on the tail. Sensory filaments, however, are also given to the skin. The first eleven of the inferior divisions of the lumbo-caudal nerves do not enter into the formation of the great inferior cord. They correspond to the lumbar and sacral nerves in man. The large internal pudic nerve takes origin from the more posterior of these. Recent additional Observations on the Physiological Action of Sight, On the Action of Vanadium upon the Intrinsic Nervous Mechanism of the Frog's Heart. By Prof. ARTHUR GAMGEE, F.R.S., and LEOPOLD LARMUTH. Method of Experiment.-A frog's heart was arranged with an artificial circulation, the blood (i. e. rabbit's serum) passing from a reservoir of given height through the auricles, ventricle, and bulbus aorta, and being allowed to trickle back into the reservoir down the sides of a glass rod, so as to be exposed in a thin film to the air. In the course of this artificial circulation a mercurial hæmodynamometer was interposed, arranged so as to record its movements on a blackened cylinder. Before taking a tracing the outlet of the blood from the circulating system back into the reservoir was obstructed, thus causing the mercury in the distal manometric limb to rise and oscillate. Normal tracings were first taken; then the serum was mixed with a solution of a sodium salt of vanadium (NaVO, or NaVO,, or Na, VO), and other tracings taken at intervals. When the effects of vanadium-poisoning were well advanced the vagus nerve was stimulated in certain cases and the effects noted. In other cases atropin-poisoning was induced prior to mixing the serum with the salt of vanadic acid. Results of Experiments.-When vanadized serum flows through a beating frog's heart (being present in a proportion of 098 per cent. of V,O,) the force of ventricular systole is much diminished, the ventricle passes into persistent contraction for a time, while the auricles pulsate as usual or somewhat enfeebled. If the proportion of vanadium were twice as large, the ventricle stops writhing one or two minutes in a state of rigid contraction, in which it continues for a long time, often, however, relaxing again before death. When so contracted, excitation of vagus, sufficient to stop the auricles, has no effect on the ventricle. The previous administration of atropia does not in the slightest modify the above results. On the Difference in the Poisonous Activity of Phosphorus in Ortho-, Meta-, and Pyrophosphoric Acids. By Prof. ARTHUR GAMGEE, F.R.S., JOHN PRIESTLEY, and LEOPOLD LARMUTH. In their experiments the authors made use of frogs, rabbits, and dogs; and the sodium salts of the phosphorus acids investigated were introduced into the system either subcutaneously or by venous injection. The salts used were trisodic orthophosphate, tetrasodic pyrophosphate, and sodic metaphosphate, the standard solutions being made to contain the same amount of phosphorus calculated as P2O.. As the result of their experiments the authors state: 1. That trisodic orthophosphate is physiologically inactive. 2. That sodic metaphosphate is a poisonous substance, but not so poisonous as pyrophosphate of sodium. 3. That tetrasodic pyrophosphate is a body of great poisonous activity, inducing death without materially affecting the irritability of voluntary muscles or of nerves. It exerts an action on the spinal cord and medulla oblongata not unlike that exerted by sodium salts of vanadic acid. On the heart its action is similar to that of salts of vanadic acid. On general nutrition and on the alimentary canal (when any action resulted) the effects were like those of poisoning by phosphorus, viz. fatty degeneration of kidneys, muscular tissue of heart and of liver on the one hand, and hæmorrhagic infarctions and brown patchy congestion of the alimentary mucous membranes. When introduced into the alimentary canal fatal results never followed, this being probably due to rapid elimination. On the Action of Pyrophosphoric Acid on the Circulation. By Prof. ARTHUR GAMGEE, F.R.S., JOHN PRIESTLEY, and LEOPOLD LARMUTH. The authors described experiments on rabbits and frogs in which sodium pyrophosphate was introduced into the system, chiefly by venous injection. They discovered in rabbits a twofold change in the circulation, occurring within 6-25 seconds after injection of the drug, viz. (1) a fall in blood-pressure and (2) a marked slowing of pulse-rate, which they believe they have proved to be due to an action on the vaso-motor centre in the medulla oblongata and an action on the intrinsic motor mechanism of the heart respectively. On the Brain of the Canidae. By ROBERT GARNER, F.L.S., F.R.C.S. The author infers, drawing his conclusions from the measurements of the capacity and from casts of the interior of the skulls of different dogs, that the size of the brain does not very closely correspond with the size of the animal. He is also disposed to argue for the derivation of our domestic dogs from one or more wild dogs; but of the more remote origin of the latter he does not propose to treat. From the table it will be seen that no dog has so large a brain as the wolf, or one so small as the jackal, from both which animals he has been supposed to have been domesticated; his brain seems specific in size. Though Mr. Darwin has shown that the large tame rabbit has a smaller brain than the wild one, yet we could hardly suppose that the dog, if he were a domesticated wolf, would have his brain so diminished, the circumstances of the two cases differing very widely. For similar reasons, if either the wolf or the jackal must be assigned as the source of the domestic dog, perhaps preference must be given to the latter. Little account need be taken of the likeness often seen between these different animals, or of the similarity of the cerebral folds, any more than of the corresponding circumstances in the Felidæ. Though neither the size of the brain nor the intelligence of the dog increase in the exact ratio of the size of the body, yet the two former seem to correspond better to each other. In large dogs the skull, as a whole, rather than its braincavity increases, and this for muscular attachment, size of teeth, &c. But it is not easy to advance further and connect the various powers of dogs with any peculiarity of brain organization. In dogs with fine scent, as the hound, the rhinoncephalon is elongated or enlarged and the whole brain also lengthened, and this throws back the three arched folds which are situated over the fissure of Sylvius; the smaller dogs, noted for acuteness of smell as well as sagacity, as the terrier, may have a short but deep rhinencephalon, fuller convolutions, and the arched folds more upright. A distinct inner and anterior lobule is seen in front of the upper transverse sulcus, as well as in the hog, sheep, and horse, but little developed in the cat, where smell is less acute; in the sheep it is covered with pigment like the olfactory nerve, and it appears to be the terminus of the inner root of the nerve. The above description comprises most of what is seen on the surface of the brain, and the elongated and simple folds, of which, however, the upper one is bifurcated before and behind, somewhat correspond with Mr. Swan's later dissections, obscure as is his text; there is, however, a superadded tract bordering the longitudinal fissure on each side, connected with the inner surface of the hemisphere, and bounded in front by the transverse or crucial sulcus, also forming behind an occipital portion lying under the supraoccipital lamina. In these different convolutions there are certainly minor variations in different dogs. When we see that the brain of the dog is no larger and not more convoluted than that of the sheep, we must infer that he owes his sagacity in a great measure to the training and companionship of his master. But no doubt he had its germs by nature, together with fine scent, fleetness, watchfulness, and hunting propensities; he hence became, as Cuvier expresses it, "la conquête la plus complète, la plus singulière et la plus utile que l'homme ait faite." In the Table several of the above facts will be manifest; for.instance, the Newfoundland dog, though it was so sagacious as to rescue a drowning man at Southport, and though the weight of its body would have been four or five times as much as that of one of the small terriers, had its brain only about one fifth larger than these last. The capacities of the skulls were ascertained by measuring the interiors by means of sand, and reducing to the equivalents of the natural contents. On the Unwholesomeness of Flesh Diet in Tropical Climates. Über die Physemarien (Haliphysema und Gastrophysema), von ERNST HAECKEL. Diese kleinen Zoophyten, welche auf dem Meeresgrunde festsitzend leben, gehören zu den ältesten und einfachsten unter allen Metazoen und stehen in erwachsenem Zustande unter allen Thieren der Gastrula-Form am nächsten. Haliphysema ist zuerst von Bowerbank als eine kleine Spongie, Gastrophysema hingegen (unter dem Namen Squamulina scopula) von Carter als ein Rhizopode beschrieben worden. Beide Genera zusammen bilden eine besondere kleine Klasse von Zoophyten, welche der Vortragende Gastraeaden nennt, und welche weder mit den Spongien noch mit den Hydroiden vereinigt werden können, da sie die unterscheidenden Charaktere beiden in sich vereinigen. Eine ausführliche, von 6 Tafeln begleitete Abhandlung über diese Gastraeaden hat inzwischen Professor Haeckel veröffentlicht in der 'Jenaischen Zeitschrift für Naturwissenschaft,' vol. xi. Heft i., 20. März 1877. Separat-Abdruck in den 'Studien zur Gastraea-Theorie.' On the Dynamics of the Racial Diet in India. By Surgeon-Major JOHNSTON. On the Action of Alcohol on the Brain. By CHARLES THOMAS KINGZETT, F.C.S. London and Berlin. The question of what becomes of alcohol taken into the system has been extensively studied. Thudichum was the first to determine quantitatively the amount of alcohol eliminated by the kidneys from a given quantity of alcohol administered, and the result which he obtained was sufficient in itself to disprove the "elimination" theory at that time widely prevailing. Dupré and many others continued these researches, from which, to use Dupré's own words, we may fairly draw three conclusions (see 'Practitioner,' March 1872, being abstract of a paper communicated to the Royal Society) :— (1) The amount of alcohol eliminated per day does not increase with the continuance of the alcoholic diet; therefore all the alcohol consumed daily must of necessity be disposed of daily; and as it is certainly not eliminated within that time, it must be destroyed in the system. (2) The elimination of alcohol following the taking of a dose of alcohol is completed twenty-four hours after the last dose of alcohol has been taken. (3) The amount eliminated in both breath and urine is a minute fraction only of the amount of alcohol taken. Now Dr. J. Percy in 1839 published a research on the presence of alcohol in the ventricles of the brain, and, indeed, he concluded "that a kind of affinity existed between the alcohol and the cerebral matter." He further stated that he was able to procure a much larger proportion of alcohol from the brain than from a greater quantity of blood than could possibly be present within the cranium of the animal upon which he operated. Dr. Marcet, in a paper read before the British Association in 1859, detailed physiological experiments which he considered to substantiate the conclusions of Percy, inasmuch as they demonstrated that the alcohol acted by means of absorption on the nervous centres. Lallemand, Perrin, and Duroy had moreover succeeded previously in extracting alcohol from brain-matter in cases of alcoholic poisoning. But all these researches leave us entirely in the dark as regards the true action, if any there be, of alcohol on cerebral matters. And no method of investigation was possible until the chemical constitution of the brain was within our knowledge. Thudichum's recent researches in this direction, together with some more recent and published investigations by Thudichum and the author, have placed within reach new methods of inquiry regarding the action of alcohol on the brain. In my research I have attempted this inquiry, by maintaining the brains of oxen at the temperature of the blood in water or in water containing known amounts of alcohol. The extracts thus obtained have been studied in various ways and submitted to quantitative analysis, while the influences exerted by the various fluids on the brains have been likewise studied. These influences extend in certain cases to hardening, and to an alteration in the specific gravity of the brain-matter. Here I shall simply state in the fewest words my results and the conclusions to which they lead. Water itself has a strong action upon brain-matter (after death), for it is capable of dissolving certain principles from the brain. These principles include cerebrine (CHNO), myeline (CH,NPO,), and apparently a new phosphorized principle insoluble in strong alcohol, together with that class of substances generally termed extractives. At the same time the brain swells and attains a smaller specific gravity: thus in one case from 1036 it became 1007. It is notable that water, however, dissolves no kephaline (C12H.,NPO13) from the brain. 79 42 79 Alcohol seems to have no more chemical effect on the brain than water itself, so long as its proportion to the total volume of fluid does not exceed a given extent. The limit would appear to exist somewhere near a fluid containing 35% alcohol. But if the percentage of alcohol exceeds this amount, then not only a larger quantity of matter is dissolved from the brain, but that matter includes kephaline (CH,NPO). Such alcoholic solutions also decrease to about the same extent as water the specific gravity of brain-substance, but not from the same cause; that is to say, not merely by the loss of substance and swelling, but by the fixation of water. Many difficulties surround the attempt to follow these ideas into life, and to comprehend in what way each or all these modes of action of water and alcohol on the brain may be influenced by the other matters present in blood. From Thudichum's researches it follows that the brain must be subject to every influence affecting the blood; and it is probable, on consideration, that what is written above regarding the action of water on the brain is likewise true of an extraordinary watery serum in life. But if the serum be rich in salts, those salts, by a power of combination which they have for the cerebral principles, would preserve the integrity of the latter. On the other hand it is difficult to see how any of the matters known to exist in the blood could prevent alcohol, if it were present in sufficient amount, either from hardening the brain (as it does after death) or from dissolving traces of the principles to be henceforth carried away in the circulation. That is to say, should physiological research confirm the stated fact that the brain in life absorbs alcohol and retains it, it would almost follow of necessity that the alcohol would act as I have indicated and produce disease, perhaps "delirium tremens." On the Poisonous Activity of Vanadium in Ortho-, Meta-, and Pyrovanadic Acids. By LEOPOLD LARMUTH. The author concludes from certain experiments detailed that the toxic intensity of orthovanadate of sodium is much less than that of the pyro- and metavanadates of the same base, but that the fundamental mode of action is the same in each. On the Action and Sounds of the Heart. By Dr. PATON. Note on the Physiological Action of Vanadium. By JOHN PRIESTLEY. The author described the methods of experiment and observation followed out in a research into the physiological action of vanadium, and concluded by stating the general results arrived at, viz. :— 1. That vanadium is a poisonous substance. 2. That the symptoms of poisoning are, in general, similar whatever the method of the introduction of the salt into the animal system. 3. That the symptoms of poisoning which appeared in one or other of the various classes of animals above mentioned are:-paralysis of motion; convulsions, local or general; rapidly supervening drowsiness or indifference to external circumstances; congestion of alimentary mucous membranes; discharge of sanguinolent fluid fæces; presence of glairy, fluid mucus in the intestines after death; certain changes in respiration, and, coincidently, a fall in temperature; drowsiness and feebleness of pulse. In addition, the heart was always irritable after death, consciousness and sensibility to pain seemed unimpaired, and no diminution could be detected in the powers of muscle and nerve to respond to stimulation. 4. That the lethal dose for rabbits lies between 9-18 and 14-66 milligr. of V2O; per kilogr. of rabbit. |