overpowered, and irregular muscular actions^ spasms, or convulsions ensue. Of these causes, none are more liable to act as excitants of convulsions than irritation of the fifth and piaeumogastrJQ nerves. Oftener than from any other causes, spasm 19 the indication of irritation in the field of distribution of the fifth nerve, or of gastric or intestinal trouble.

The profound disturbance which may be excited in a young child by slight causes is a matter of common observation. A mere interference with function may result in consequences out of all seeming proportion to the gravity of the cause. The presence in the alimentary tract of a little indigestible food; worms; a misplaced pin; continued pressure, as by a string or bandage; any considerable irritation of the cutaneous surface, will excite a more or less severe fever in proportion to the predisposing conditions present. If in the adult the irritation of a dental nerve may give rise to neuralgia, hysteria, chorea, tetanus, etc., it is not only possible but highly probable that a like irritation may be the occasion of grave and fatal disorders in the infant.

APPABATUS FOE BOTATING TEETH.

BY J. N. FARRAR, M.D., D.D.S.
[apaktmbnt No. 1, Renssecaer, 1271 Broadway, New Yoek, N. Y.]

-No. XXIV.
Double Concentric-loop Eotators.

The devices which I denominate double concentric-loop rotators, although a little difficult to construct and somewhat clumsy to wear, are extremely practical in the hands of the skillful. Fig. 141 illustrates the principle of these rotators as one of them would appear when placed upon teeth, situated as shown by dotted lines. B" in Fig. 142 shows the same device as it would appear reversed, and in detached parts by B'. As will be seen, this is but another modification of the device illustrated by Fig. 135, differing by the use of a second band outside of a clamp-band, B, which may be denominated the draught-band.

These clamp-bands, constructed to be tightened upon the tooth, may be variously made. This modification makes use of a short bolt, C. To this clamp-band, in the vicinity of the nut, N", is attached, by solder, one end of the draught-band, O. To the other end is soldered a threaded nut, P, through which passes a long screw, S, having its other extremity pivoted so as to set in a hole in the nut, P', which is soldered to or otherwise connected with the clamp-band, B, by means of a thin metallic ribbon or a wire loop, L, caught over the end of the bolt, C, in such a manner that when the i0b ftttttf,'P, F, are forced apart by the screw, S, a double draught a^ti tipon the tooth, in a direction that will tend to rotate it as indicated by the curved arrow.

Instead of connecting the draught-band, O, to the clamp-band, B, with a loop, L, to catch over the ends of the bolt, 0 (Fig. 142), it may

be made fork-like (E, E), so as to catch over knobs or hooks (K, K), soldered to the sides of the nut, P, as shown by J, A, Pig. 142.

This unique apparatus, however, is capable of several modifications without materially changing the principle of philosophy. The

above group of nine figures, illustrating several variations made by the author, is here presented for the benefit of those interested. As will be seen, the principal differences lie in the length, form, and places of attachment of the draught-band.

Various Modifications Of Botators.

Fig. 143 illustrates a modification made in three detachable parts, C, C, B, as shown. The screw, S, of the clamp-band, B, however, is on th£ opposite side of the tooth over which the looped end of the draught-band is caught, as shown by A. The other draught-nut is represented as being caught over a hook soldered to the opposite side of the clamp-band, B. The advantage of detachable parts lies in the easy repair of any one that may become broken, but the fixture is more difficult to apply than if soldered together.

Fig. 144 illustrates a similarly constructed rotator, having all its parts soldered together, which, though easy to adjust, is useless if broken, unless mended.

Fig. 145 shows how the draught-band may be soldered to the clamp-band, while the other draught-nut loop may be caught by a hook into a staple.

Fig. 146 illustrates the same, except that the draught-band is long enough to nearly encircle the tooth, and is also soldered to the clampband, B. Care should be exercised in soldering this draught-band, so that it will lie to one side of the clamp-band nuts and screw.

Fig. 147 (central figure) illustrates an excellent modification, because effectual, and, being composed of only two parts, C, B, is simple. The draught-band, C, though in two parts, is united at the loop end, so as to be easily caught over the end of the screw or hook, as the case may be.

Fig. 148 differently illustrates a modification similar to that illustrated by Figure 142, and is composed of three parts.

Fig. 149 illustrates the parts separately and unitedly of a modification similar to that represented by the central figure, 147, differing only in the length of the draught-band, C.

Fig. 150 illustrates two views of a peculiar but valuable form ol longer draught-band. While all others thus far described consist of a straight, ribbon-like strip (of rolled wire), this is open in its middle, in order to permit it to rest firmly on the tooth on both sides of the clamp-band, bolt, and nuts.

Fig. 151 illustrates also two views of a similar though more valuable form of double long-draught band, but differing only in the extent of the slot. These two forms of bands, Figures 150 and 151, are only necessary for rotators requiring a long band, such as are shown by Figures 146 and 148.

Application.—When teeth are so overcrowded that this device cannot be easily adjusted, they may be spread apart* by wedges, but easier by a triplex-acting screw-loop (Figure 135). After the rotator is adjust^, thp patient should be instructed to turn the screw, S, with a key or lever as much as possible without causing pain, two or three times a day, when the apparatus will not only keep the two adjacent teeth apart, but will rotate the middle one at the same time.

The most objectionable part of these rotators thus far illustrated is the means of tightening the clamp-band, B. The two nuts, 1ST, Wf, and the screw, G, are sometimes a serious obstacle. In order to avoid this, other means may be adopted for anchoring the draughtband to the tooth, among which the narrow ferrule, fitted around the tooth and set in phosphate of zinc, or tightened with wooden wedges or by a gum-guard ring (Fig. 100, page 348, vol. xxiii., Dental Cosmos, 1881), fitted closely and driven on to the tooth, are among the best plans. But when there is a suitable cavity in the tooth to be rotated, a small hook or staple may sometimes be temporarily set in it with phosphate of zinc or amalgam, on which the

draught-band may be caught, thus avoiding the clamp-band, B, entirely.

There is, however, a buckle method of tightening the tooth clampband, which is nearly free from these objections, and which in skillful hands will be found practicable, but its success depends entirely upon nicety of adjustment. Figs. 152, 153, 154, 155 illustrate the principle of such a device, shown in the different positions on an exaggerated plan, in order to be easily understood; but in practice the two pin bars, S, Fig. 152, should be nearer together, and the buckle frame shorter. Fig. 156 shows a still different method for the same purpose. Thes^ which are of some of my later thoughts, nearly solve a long recognized difficulty.

Metainers.-r~When single teeth, situated as shown by Fig. 138, are brought into position, they may be easily retained temporarily by the use of one of these clamp-bands, B, minus the screw, if carefully pressed up around the tooth, so that the nuts will rest over the adjacent teeth as shown by E in Pig. 141. But a little strip of gold plate, properly fitted in the same way, is better in appearance.

When there are cavities conveniently located, little wires may be set in them, so that, if properly bent about the teeth, they will serve the same purpose. But whatever form of retainer is used, it should be kept scrupulously clean.

Suggestion.—In conclusion, let me say that the success of these devices depends upon the proper delicacy of their construction and fitness in application. No bunglingly made article will work satisfactorily, if at all. This suggestion is made and urged because some persons, who have tried to make and use devices explained by me have failed for this reason, and seemingly without being conscious where the fault lay, have endeavored by criticism, publicly expressed, to persuade others that it was impossible to do things which, in fact, with the more skillful, are done with ease; and in their unfortunate bitterness they have even gone so far as to broadly hint that devices advocated (which have for years been in use with great success) have never existed except on paper.

PROCEEDINGS OF DENTAL SOCIETIES.

IEW YOKE ODONTOLOGIOAL SOCIETY.

The New York Odontological Society held a regular monthly meeting October 21, 1884, at the house of Dr. O. E. Hill, No. 160 Clinton street, Brooklyn.

The president, Dr. William Jarvie, in the chair.

Dr. S. Gr. Perry. I have thought for a long time that a great many of our most skillful operators have many times fallen somewhat short of a high standard of excellence in their approximal surface operations, because of inability, under all circumstances, to make perfect restorations of contour. It is not always possible to have the teeth wedged apart sufficiently to get such access to the cavities as we would like, because sometimes the patient cannot wait long enough, or cannot come to us to have the wedges placed or changed. Under such circumstances we have to do the best we can, and it is easy to understand how skillful men will sometimes fail to accomplish just what they would like to do. I appreciated this fact years ago, and I worked out a little device for separating teeth which could be applied and left on while the operation of filling was performed. In 1876 or 1877 I exhibited this device, in a