During the operation a strict watch must be maintained upon the respiratory functions, so that any laryngeal obstruction may be readily noticed and treated. The colour of the pinna of the ear, the mobility of the tongue, if unrestrained by a gag, and the condition of the conjunctival and pupillary reflexes assist in giving useful indications for an increased or decreased administration when the patient’s face is obscured by hands, instruments, or congealed blood. _When the conjunctival reflex is absent, and the pupil dilated and unaffected by light, the anæsthetic should be temporarily suspended._ _When the conjunctival reflex is absent, the pupil contracted, and the colour good, the patient is in the best condition of anæsthesia, and this state should be maintained, if possible, throughout._ _When the conjunctival reflex is present together with dilatation of the pupil, movements of the tongue, and other “reflex” efforts, the amount of chloroform should be increased._ During the first stage of the operation, when hæmorrhage is profuse, deep anæsthesia is undesirable for fear of blood passing into the larynx. To prevent this, after the incisions have been made, sponge pressure should be applied, and the head turned on one side. Any gurgling in the throat, or dusky colour of the face, indicating threatening laryngeal obstruction by blood-clot, needs an efficient application of a sponge on forceps behind the tongue, the effect of this being not only to remove blood, but also to stimulate closure of the glottis. The bleeding having been arrested, and the later stages of the operation reached, a deeper anæsthesia is necessary. Sudden increase or decrease of the amount of the anæsthetic will readily induce vomiting, and if much blood has been swallowed in the earlier stages, this _contretemps_ may be inevitable in spite of all precautions. DUTIES OF THE ASSISTANT. For the efficient performance of the various steps of the operation a skilled assistant is absolutely essential. His duties will consist, first and foremost, in keeping the pharynx clear of blood; secondly, in such dextrous use of sponges as will allow the parts to be clearly seen by the operator; thirdly, in the judicious use of a tongue depressor, when necessary; and fourthly, in exercising a careful supervision over the stitches before they are finally fastened. For the purpose of clearing the pharynx, he must be provided with a pair of long smooth-nosed forceps (Fig. 61 B), and some small loose pieces of purified sponge; or the sponges may be fastened on pieces of stick about six inches long in such a manner and so securely that the necessary manipulations shall not detach them. The former of these methods is, I think, preferable.