These cases (p. 165) must be very exceptional, and cannot be taken as guides for treatment. In the last case, good fortune rather than skill was the cause of the good result. If the incision had not happened to have been exactly at the point at which the foreign body lay, there would have been probably an increase of irritation, and enucleation would have been necessary. There might have been more than one foreign body, and this again would have led to the same necessity; but still the possibility of saving an eye under favourable circumstances, such as those mentioned, should always be kept in view, and the more radical measure can be resorted to if the preliminary operation fail. But in a few rare cases it may be possible to save an eye in which a foreign body is seen without resorting to any operation. I have now under observation a young man in whose vitreous I can see a small chip of metal suspended in the vitreous humour. It is exceedingly minute, and can only be seen by using a magnifying glass, but it is nevertheless evident enough, and its position and metallic character distinct enough, to make me sure of its lodgment in the vitreous. The scar of the point of entrance is also evident, and the history of the accident satisfactorily accounts for its presence. At first some irritation of the eye showed itself, but under treatment by atropine and cold applications all irritation subsided, and vision is perfectly good. I have therefore decided to leave this foreign body where it is. It is suspended in the vitreous, which is elsewhere perfectly clear, and there are no signs of irritation in any of the more sensitive and vital parts of the interior of the eye. A small blood-clot near it has become smaller and more attenuated, and the retina is quite unaffected. It will therefore be quite unjustifiable to interfere in this case by operation, unless any change takes place in the position of the chip of metal, or any inflammatory exudation occurs in its neighbourhood. Its extremely small size is an important element, because its weight will not be likely to cause any change of position, and the consistence of the vitreous will be sufficient to hold it away from any important parts.

This again is an exceptional case, but others are recorded in which metallic bodies of larger size have remained embedded even in the retina for a considerable time without causing any

serious mischief. The liability to mischief occurring at any time under such circumstances should be plainly stated to the patient, and he should be examined from time to time, as irritation might suddenly come on, and sympathetic mischief would very soon follow. Hence it will not be justifiable to lose sight of such a case without warning the patient of the danger he incurs, and placing before him the possibility of his having to submit to enucleation, if symptoms require it.

SOME REMARKS ON THE THEORY OF INHIBITORY

OR REFLEX PARALYSIS.

BY C. HANDFIELD JONES, M.B. CANTAB., F.R.S.

IN the British Medical Journal, 1874, i. p. 40, the following passage occurs in a highly interesting lecture on diabetes by Dr. L. Brunton:-"The second way in which the hepatic vessels may be dilated is by reflex paralysis, or inhibition, as it is generally termed, of their vaso-motor nerves. Everyone knows that when a sensory nerve is irritated, the impression is transmitted to the vaso-motor centre, and arrests its usual action over the vessels of the part to which the sensory nerve is distributed. Thus, when a grain of sand falls into the eye, the irritation which it occasions to the sensory nerves of the conjunctiva is conveyed by them to the vaso-motor centre, and arrests the action of that part of it which regulates the contraction of the conjunctival vessels. In consequence of this, they become dilated and full of blood, and continue so while the irritation continues; but so soon as it is removed the vasomotor centre again regains its wonted power, and the vessels return to their normal size. The same is the case with the liver, and its sensory nerve is the pneumogastric." Lovén's experiment on the auricular nerve of the rabbit, Rutherford's demonstration of the inhibitory action of the vagi on the gastric blood-vessels, Bernard's of that of the gustatory nerve on the vessels of the submaxillary gland, and Cyon's of the action of the depressor nerve of the heart on the intestinal arteries through the splanchnics, constitute, I suppose, the chief experimental evidence in favour of the view above stated, which