could be obliterated, apparently by overcoming the contraction of the muscular tissue. These facts are elucidated by a collateral experiment. If the stomach and intestines of a cat or dog, immediately after death, be exposed, imperfect wheals (but essentially wheals) may be formed upon them by passing a point sharply over their surface. plainly the result of muscular contraction. These are When we consider the rapidity with which the eruption forms, its noticeable gradations through cutis anserina, the hardness and sharpness of its outline, the conditions which modify it, and the parts of the surface where it is most readily excited, and its non-occurrence on others, the conclusion above stated seems irrefragable. How a wheal is excited in ordinary urticaria, whether directly by the circulation of some irritating substance through the cutaneous tissues, or indirectly by reflection through the vaso-motor nerves, or indifferently by both modes, is not proved. Admitting that the blood is the more common channel, there are still many clinical facts, as well as the proofs given above, which show that it is not the exclusive one. It is well known that exciting or depressing emotions will favour the eruption, and sometimes it seems to be caused by merely thinking of it. We are so much in the habit of viewing these phenomena as evidence of the elimination of a materies morbi, as an "effort of nature" to throw off what is offensive, that we are prone to overlook all other modes of action. ON THE EFFECTS OF ETHER ON THE DIFFERENT CLASSES OF ANIMALS.1 Ir a mammal or bird be made to inspire atmospheric air strongly impregnated with ether vapour, in from sixty to ninety seconds its muscular power is lost; it becomes totally insensible to pain; its respiration becomes slow and irregular in rhythm; the venous blood is of a vermilion colour; the heart beats with great rapidity; its rhythm is irregular, and its force diminished. If the experiment be made with a frog, the effect is produced in nearly the same time; considering, therefore, the slowness of its respiratory movements, the mixed nature of its circulating currents, and the lowness of its temperature, it becomes more rapidly affected than a mammal or a bird. The state of etherisation, when induced, is also more perfect and lasting than in warmblooded animals, the respiratory movements in frogs being often arrested for six or seven minutes. Alcohol vapour produces similar effects; they are slower in their accession and more lasting in their effects, often fatal. An increased flow of saliva is one of the ordinary effects of the inhalation of ether; this was observed in man, in cats, mice, and birds. The irregularity of the muscular movements A paper read before the South London Medical Society, April 15th, 1847. Reprinted from the 'London Medical Gazette,' vol. xxxix, p. 777. (The paper is reproduced as it is reported. Its historical value is so great that it could not be entirely omitted. The complete paper, if it was ever written, has been lost.-ED.) which come on amongst the early effects of etherisation do not seem to depend so much upon want of muscular power as upon a loss of muscular sense that is, the power of appreciating the force of the muscular contraction, and the exact locality of the limb. The phenomena produced by the inhalation of ether vapour are allied to those which result from alcoholic drunkenness; the former are more transitory, and more speedily induced. If drunkenness either by ether or alcohol is extreme, it will terminate in asphyxia. Some of the phenomena of ether drunkenness are induced by concussion. In both states the surface is often cold, pulse irregular and frequent, respiration irregular in rhythm and force; no recollection of occurrences during the stage of concussion or etherisation; memory of events long past wonderfully recalled both by concussion and etherisation. Ether in some persons produces extreme faintness and sickness, with trembling and paleness; concussion does the same. In concussion, as in etherisation, patients are occasionally violent, swearing and manifesting the phenomena of drunkenness. It has been considered a remarkable fact, that, by the inhalation of ether, common sensation should be lost, whilst the senses of hearing and seeing are so little impaired. Such a state is occasionally observed in nervous exhaustion alone; two classes of such cases might be enumerated,-bilious disorders, and after venereal excesses. In such cases the gait and other muscular movements may be awkward, arising from this diminution of sensation only, and not from muscular weakness. The phenomena arising during the inhalation of ether are not at all dependent upon super-carbonisation of the blood. Frogs are rapidly affected by ether vapour, whilst they may be kept for hours in hydrogen and nitrogen without injury. Pure ether vapour killed a bird past recovery in twenty-five seconds. Ether probably permeates every tissue, but acts most upon the nervous, on account of its physical constitution, the grey substance of the brain containing 4'5 per cent., the medullary substance 14'5 per cent. of fatty matter. irritability of muscular fibre in frogs is not evidently diminished by ether. Ether probably produces its effects The |