M. Petit in 1750 communicated to the Royal Academy of Surgery at Paris, a description of a new elevator plate, with reflections on those hitherto used. He says the instruments hitherto used to raise the bones of the cranium depressed on the dura-mater are principally, the common elevator, the claw or the griffin's foot, and the triploid with or without the terebra, and sometimes the terebra alone. The triploid has three feet or branches like a tripod; these rest on three points at small distances with the wound under the vault or arch formed by them. The moving force was applied with a nut, which received the screw of the upper end of an upright shaft, whilst the lower part had an extremity bent in the form of a hook, which is introduced under the bone to

be raised, so that by turning the nut to the right the screw is gradually raised. It was an instrument that could hardly be used except by operators of great dexterity, and was therefore rarely used. These reflections induced him to contrive an elevator to which is attached a kind of bridge laid on the cranium for leverage and to which it was screwed. The lever was eight inches long, five lines broad and two thick; the distal end grooved in front, the under part rounded and polished, that it may not wound the duramater. The surface of the under part had several holes in the middle, made lengthways, wormed, and served to receive a screw which bound and fixed the lever fulcrum. The second part of the elevator is like the bridge of a violin, and when fixed on the cranium only touched on its two

extremities. At the top of the bridge is the screw before mentioned, which when fixed in the screw holes fixes it to the lever. The bridges are made in several sizes to be used in the different cases which may occur in practice.

With regard to the inventor of the trephine and how it received its name I can say nothing definite, it is probably the outcome of the trepan (trephine, diminutive of trepan, from the Latin trepanum, Greek trapanon, TрUTаW, to bore). It was first made with the handle of iron, the extremity of

The trephine of to-day.

such handle formed in such a manner as to serve the purpose of an elevator, thus combining, as it were, two instruments in one. This, Mr. Pott thought a great fault, because it added to the weight of the instrument, and that in a wrong part of it, and thereby rendered it less manageable. He recommended that the handle should be of light wood, not too long, and of an octangular shape, and that from the figure depicted in his work with slight modification, is the trephine of our day.

Mathieu's trephine is a useful little instrument, much smaller than the one formerly used; its action also is more reliable and regular and less sensitive to shocks.

It may be interesting if I endeavour to throw some light upon the manner in which the earliest writers were wont to make their incisions, in laying bare the skull previous to the operation and their subsequent treatment of the dura-mater (for this information I am largely indebted to a little work by Robert Mynors).

Hippocrates, B.C. 400, gave no particular directions for the incision of the scalp previous to the use of the terebra, but in speaking of wounds of the head where the bone has been denuded, he directs1 the incision to be made in the

Pott's trephine.

superior part, sufficiently large to ascertain whether the bone be injured and to separate the flesh from the bone, further observing that the section of the parts for this purpose ought not to be made on the temples nor above the temporal artery-for convulsions on the opposite side would be set up. In cases where the injury seems to require perforation we must have recourse to it within three days, and recommends where the dura-mater is denuded, that it should be cleansed and exsiccated as soon as possible lest it be kept moist too long, it becomes spongy and rises into a fungus or putrifies.

166

Hippocratis Opera, edit. Charlerii lib de Vuln.”

Celsus,1 A.D. 30, followed the Hippocratic method, which for four hundred and sixty years had been practised almost without change. He recommended the wound to be enlarged till the injured part appear, and that none of the peri-cranium be left on the bone, for that when lacerated by the scalprum or terebræ would excite violent fever with inflammation. If there be a wound it is necessary to dilate in the course of it, but if we are to make one that form is generally most convenient, which by two transverse lines gives the figure of the letter X that the scalp may be afterwards raised up from each angle. After the operation he directs the dura-mater to be sprinkled with sharp vinegar, that if there be any hæmorrhage it may be suppressed, or any coagulated blood remain within it may be dissolved; if the dura-mater puff up by inflammation, tepid oil of roses should be poured upon it. When things go on well he observes that granulations spring up from the dura-mater and from the diplöe of the cranium, filling up the vacuity of the bone, and sometimes even to grow above the bone, but when that happens it is to be sprinkled with squamæ æris to suppress and restrain it, and to use such other dressings as will produce a cicatrix.

"Salvianus mentions a lunatic who by accident had the skull broken and was 'exceedingly cured,' and another, who, breaking his head from a fall from on high, was instantly recovered from his dotage; Gordonius recommended the head to be shaved and bored to let out fumes which without doubt will do much good.' I saw a melancholy man wounded in the head with a sword, his brain pan broken; so long as the wound was open he was well, but when his wound was healed his dotage returned again. Guianerius cured a nobleman in Savoy by boring alone, leaving the hole open a month together, by means of which, after two years' melancholy and madness, he was delivered." (Burton.)

Heliodorus2 wrote that he did not use one method only of incising the soft parts, but adapted it to the form and nature of the fracture, for sometimes in a fissure, he says, a simple incision is proper, but he mostly used that form which by

"Celsus de Medicina." Ed. Krause.

"Heliodorus de Fracturis, ex. Nicetana collectione per Cocchium."