There are many other names in the history of attempts at intubation during the first half of the century, two of the most important of which are Liston and John Watson, who, as the result of chance observations in cases in which feeding-tubes were inadvertently passed into the larynx, came to the thought that the larynx might tolerate a tube much better than had been previously imagined. About the middle of the nineteenth century there was no little discussion with regard to the possibility of applying remedies within the larynx after the insertion of a tube, and a large number of medical articles appeared thereon. Diefenbach, the great German surgeon, interested himself in this matter particularly, and protected his left index-finger by a shield that acted also as mouth-gag in inserting the tubes. This technique was afterward to be made use of by O'Dwyer. The first great step in intubation, as we know it at the present time, however, came from Bouchut, who suggested the use of a tube about the size of a thimble meant to be inserted into the larynx. At the upper part of this tube there were a pair of rings, between which the vocal cords were supposed to rest and hold it in place. Bouchut operated in seven cases with his tube, but five of his patients died, while two of them recovered only after tracheotomy had been performed. Bouchut succeeded, however, in showing that the larynx would tolerate a tube, though he made exaggerated claims for his method, while the very imperfect instruments he employed foredoomed his inventions to failure. It happened, moreover, that the time was unpropitious. Trousseau had not long before re-invented tracheotomy, and had employed it with considerable success in cases of croup. Under Trousseau's influence, a committee of the Academy of {339} Medicine of Paris declared Bouchut's method unphysiological and impracticable. Moeller, of Koenigsberg, tried to reintegrate Bouchut's method with certain ameliorations, but failed. The field of intubation--and a very discouraging one it seems, strewn as it was with failures made by many excellent workers--was left for O'Dwyer to exploit. How thoroughly he worked out his methods can best be appreciated from the fact that no improvement of importance has come since he presented to the medical profession the intubation system as he had elaborated it some fifteen years ago.