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PHOTOGRAPIIING THE THROAT. BY DR. MUSEHOLD, BERLIN. In my experiments in attempting to produce a serviceable photographic picture of the throat, I started, in the first place (in the early part of 1890), with the idea of inserting a photographic apparatus between the mirror which is lighting the throat, and the eye of the researcher, in order to observe the throat picture on a focussing-screen just as it is seen by means of a laryngoscope. It is known that in previous experiments of this kind the results have been hardly satisfactory. This is shown by the last meritorious communication of Dr. Wagner (Berlin Klin. Weekly Gazette, 1890, No. 50) ; and the same failure had been already distinctly mentioned, and with justice, by Dr. Riesenfeld (Photographic News, Berlin, 1891, March, Part I). In my apparatus (which I constructed for the purpose), as soon as the picture of the throat thrown on to the ground glass shows the necessary sharpness and the desired position for photographing, the sensitive plate is rapidly made to take the place of the focussing-screen, and then the picture is taken by means of a magnesium flash-light. The changing of plates takes place by the help of the petroleum or gas light used in laryngoscoping, while the magnesium flash light (Dr. Meithe) is so fastened on to the arm which joins the reflector and its lamp that the magnesium light, when produced, and the lamp flame are nearly concentric. opening of the same size in the back wall of the camera, which remains shut. In the inside of the case is a slide, occupying its whole breadth, but only two-thirds of its length, which consists essentially of a board, with a bar fastened on the side. The latter projects 5’5 cm. from the right-hand short side of the case, according to the position which the case takes on the camera. In this position the slide fills up the two-thirds of the case lying to the right. The left half has an opening measuring 3 by 3 cm., which, in the just mentioned posi tion, therefore, is concentric with the two openings of the case, by reason of the handle being drawn out. This opening in the slide towards the front—that is, towards the camera—is covered with a ground glass; the right half of the slide has, on the front side, a support closed at the sides and underneath by ledges, and open at the top, which serves for the reception of the photographic plate. The sliding board which forms the back wall of the sup port, and also the velvet straps which are laid on the edges of it, prevent the plate being exposed to unnecessary light. The latter is pushed into the support through a closable slit, which is in the upper narrow long side, and which is made light-proof by means of a shutter. As soon as the picture is clearly projected on the ground glass, the slide is pushed, by means of the bar or handle, to the left to the end of the case, and consequently moves the sensitive plate, which is Half size of case. Bick wall has been removed. A. Case. a. Slit closed by a shutter. B. Back of slide, i. Bar f. r moving, o. Flace for sensitive plates, d. Ground glass fastened on to front side. The camera with the reflector, which is held by the universal jointed arm of Tobodd’s laryngoscope, is fastened to the base of an ordinary strong head-rest by means of a screw, so that an approach to the object and a horizontal movement is possible. The apparatus permits in this way of being placed between the patient and the physician without trouble. As lens, I have hitherto used (in order to obtain pictures as large as possible), first a Hartnack- Anastigmat of 11 cm. focal distance and 11 mm. aperture, and latterly a Steinheil-Antiplanet of 12’5 cm. focal distance and 21 mm. aperture. The reflector is the one customarily used in laryngoscoping, of about 20 cm. focal distance, and with a central hole of 20 mm. The principal part of this on the whole very simple apparatus is the case. While at other times the lens is found in the camera, I have for this above-mentioned purpose placed it in the case. The latter is erected for plates 4 by 4 cm. in size, and consists of a box which is 15’5 cm. in length, 5 cm. in breadth, and 1'5 cm. in thickness; it has an opening 3 by 3 cm. in diameter in the centre of each of its sides. One of these openings, namely, that in the front side of case, has around it a ledge with sloping inner edges; this is to form a groove for corresponding ledges, which are arranged dove-tail fashion round a central on the same level, behind the front opening of the case—that is, where the ground glass was standing before. The same hand which pushes the slide immediately turns on the flash-light, and pulls the slide back again to the right by the handle, which still sticks out. The light which falls on the sensitive plate from the gas or petro leum flame during the pushing back wards and forwards of the slide has no influence on the sharpness of the picture ; this has been proved with this case by some very successful portraits of children. After the operation is finished, the case must be taken into the dark room, and the plate removed and deve loped. Naturally, the photograph can be done only in a room from which the daylight is quite excluded, or in the even ing. But this disadvantage can be set aside by placing an instantaneous shutter on the slide itself in front of the sensitive plate, which should be put in motion as soon as the slide has been pushed right up to the other side of the case. Then, with the help of a magnesium light, the photographing can take place at any time of day. The results at which I have arrived at hitherto are certainly encouraging to the continuance of experiments in this line. The size of the picture of the throat is from 3 to 8 of the natural size. Although my experiments are not yet terminated, I have thought it advisable to describe the above arrange ment, and especially the case, in order to facilitate the troublesome work to all those who occupy themselves with this subject, or to stimulate them a little to successful improvements of the simple apparatus described. I hope before a very long time to be able to go more deeply into this subject in these columns.—Abstracted and translated from Photographuches Wochenblatt.