Natural History. 245 



space, and I mention it merely as a well-known fact, to show the 

 value of allowinfif the root or fangs of a tooth to remain. This ope- 

 ration I have called the operation of excision, and I recommend it as 

 a most valuable substitute for the extraction of the teeth in the 

 majority of cases of caries ; but by no means to supersede it alto- 

 gether, as there are, and must ever be cases requiring the entire 

 extraction of the teeth, when disease has proceeded beyond a 

 certain point, as for example, beyond the common cavity, which I 

 have cursorily described ; or when the jaw itself is diseased. 



The instruments employed by me in this operation are forceps 

 accurately iitted, like those for extraction, to the necks of the teeth, 

 but having fine well-tempered cutting edges ; these edges must be 

 carefully applied on the necks of the teeth as close to the gums as pos- 

 sible, taking care to keep the edges parallel to the edges of the gums, 

 which are to be depressed a little with the inferior surface of the 

 blades of the forceps, so as to bring the cutting edges fairly beneath 

 the enamel, which in the adult is the criterion of being below the 

 common cavity of the tooth. Then, with a gradual application of 

 pressure on the handles of the forceps, the tooth is in an instant 

 snapped off at the neck, and the common cavity, the seat of pain, 

 is thus removed, leaving the patient a painless bony surface for 

 mastication, a firm prop for the support of the adjoining teeth, 

 and a basis for an artificial tooth if it should be required. I may 

 mention here a fact never before noticed, namely, that the openings 

 by which the minute canals terminate in the common cavity, become, 

 soon after the excision of the crown, plvgged up with bony matter, 

 which thus affords a permanent protection to the interior of the 

 stump, and presents a continuous and firm surface for after-life. 

 In addition to these advantages, the operation is performed even 

 on the largest teeth in a moment, and, consequently, at a great 

 saving of suffering, which should be the grand object of all sound 

 surgery. — Trans. Soc, Arts. xliv. 70. 



11. Poisoned Wounds. — At the Academic Royale de Medecine, 

 M. Bouilland lately read a paper on some experiments relative to 

 the effect of compression on poisoned wounds. Nine experiments 

 were made. In the first five M. Bouilland introduced two or three 

 grains of strychnia into the cellular tissue of the thigh of a hare, so 

 that he could at will use compression on the limb, either by a liga- 

 ture above the wound, or with an unexhausted cupping-glass, or 

 with the hand alone placed on the wound ; and he found that he 

 could, by applying the compression or not, either prevent or pro- 

 duce the effects of the poison. He found, by many trials, the good 

 effects of compression in causing the symptoms to cease or re-appear 

 alternately according as he applied or removed the instruments. 



In a sixth experiment six leeches were applied around the little 

 wound, into which the strychnia was introduced, and it was re- 

 marked that, though none of them would bite, yet they all died. 



In the three last experiments M. Bouilland used half a teaspoon- 



