340 Dr. A. J. Wall. On the [June 16, 



tongue becomes motionless and hangs out of the mouth, and the 

 saliva which is secreted in large quantities runs down the face, the 

 patient being equally unable to swallow it or to eject it. It is singular 

 that the striking resemblance of these symptoms to the disease known 

 as glosso-laryngeal paralysis has not been previously noticed. Now, 

 the preponderance of opinion attributes this latter disease to lesion of 

 certain tracts in the medulla oblongata. It cannot, therefore, be 

 thought anything but reasonable to connect both diseases with paralysis 

 of those centres in the medulla oblongata which are so closely associated 

 together, and which are in connexion with the roots of the vagus, the 

 spinal accessory, and the hypoglossal nerves, and the lower nucleus of 

 the facial. But the resemblance does not end here. In both diseases 

 the respiration becomes feebler and feebler, and the victim at last dies 

 suffocated. In other words the lesion in the one case, and the paralysing 

 poison in the other, have invaded the respiratory nucleus so near to the 

 centres they have already destroyed, and have thus rendered the respira- 

 tory act difficult, and at last impossible. Lastly, after all the lower 

 centres have been completely paralysed, the one by which connexion is 

 made with the second, fifth, and seventh nerves still acts, and the eye is 

 closed when touched, and even when approached, after the animal is 

 dependent on artificial respiration for life. For these reasons it seems 

 natural to conclude that the principal action of cobra poison on the 

 nervous system consists of an extinction of function, extending from 

 below upwards, of the various nerve-centres constituting the cerebro- 

 spinal system; but in addition to this, there is a special and rapid 

 action on the respiratory and allied nuclei, and it is to this special 

 action that death is to be attributed in most cases of cobra poisoning. 

 In very rapid cases of poisoning, when a very large quantity of poison 

 has entered the circulation at once, instead of the gradual extinction 

 of function of the cerebro- spinal centres, the poison appears to act 

 almost immediately by stopping the action of the respiratory centre. 

 There is, of course, no time then to watch the gradual extension of 

 the influence of the poison on the nervous system. In these cases, the 

 slight stimulation of the centres which almost always precedes the 

 paralysis, instead of being represented by slight irregular contractions 

 of the muscles, is exaggerated into violent clonic convulsions, but they 

 are almost instantly followed by complete paralysis. 



The action of the cobra poison on the respiration is of the deepest 

 importance in the light it throws on the special action of the poison, 

 and its relation to other poisons. 



The first change that is noticed in the breathing of an animal after 

 the introduction of cobra poison, is a decided quickening and deepen- 

 ing of the respiratory movements. Sir Joseph Fayrer and Dr. Brunton 

 have shown that this effect is no longer to be perceived after section of 

 both vagi. The inhibitory effect of section of the vagi may be too power- 



