Operator's Hand Research Articles

A Simple Method of Mounting Small Exhibit Specimens of Mammals and Birds

At regular intervals, biology teachers are confronted with the problem of presenting their work graphically to boards, patrons and laity. Biology teachers in high schools and colleges are frequently charged with the task of preparing such exhibits in order to found or expand the Museum of the Biological Department as a teaching adjunct. Because an expense acount seldom envisages the preparation of these demonstrations, professional assistance cannot be readily procured. It is for the above reasons that I believe my simple method of mounting small mammals is worth placing on record. This technique was first applied to mouse specimens exhibited at the Harvard Tercentenary in 1936, and more recently it has been employed on rats for the museum collections of the Wistar Institute, where they will be pointed out upon request. There is no reason why this method can not be readily extended with modifications to small birds and mammals generally. For the sake of simplicity I shall here describe the method as applied to the rat. First, kill the rat with a lethal dose of ether, or chloroform or by some other method that will not harm the anatomy. Inject 10 cc of 40 per cent. formaldehyde into the thoradie cavity and another 10 cc into the abdominal cavity, massaging the animal to distribute the injection fluid within the body cavities. Inject smliall amounts into the legs and subcutaneously over the body. Within 15 minutes to half an hour subsequent to this injection the body will stiffen. When fairly rigid, place the rat upon a small temporary base-block of wood in the position desired for the finished specimen. Brad the rat's tail to the block. Then brad the four feet to their proper positions bending the body into the pose desired. The hips may be prevented from moving laterally by hammering several 7-penny nails into the block adjacent to the hips. The head may be held up by resting the teeth on a block of proper dimensions. See Fig. A. When the animal is in the position desired, allow it to stand an hour or so until it has completely hardened. Invert the specimen and wash it thoroughly under a faucet so water will wet the whole outer surface of the skin. Place the inverted specimen, block and all, into a jar of formalin and allow it to stand 24 hours. The previous washing removes all air caught in the fur that might prevent areas of the skin from coming in contact with formalin. After the specimen has cured 24 hours in formalin, wash under the faucet for a few minutes to remove all traces of formalin, which will attack the skin of the operator 's hands, unless they are otherwise protected. Lay the specimen on its back, and with a sharp razor blade cut the skin along the mid-ventral line from throat to geni1 Reprinted in part from Science.

Safeguarding the Patient and X-ray Technician from Infection in Radiodontia

It is very apparent that this is an opportune time to call the attention of physicians and dentists to the possibility of infecting one patient from another in the process of exposing dental films. Not uncommonly there are secondary, and occasionally primary, syphilitic lesions in the mouth that are not always recognized even by physicians, let alone laymen, who are employed to make exposures of such films. It has been the practice in the Mayo Clinic for several years to follow a definite procedure in order to eliminate the possibility of infecting, not only the patient, but the operator. It is assumed that the films come from the manufacturer fairly clean, or it would be necessary to sterilize them as the boxes are opened. The operator uses rubber gloves and does not change for each patient unless the condition of the mouth is questionable; however, the gloved hands are washed with a liberal amount of soap and water followed by alcohol for each case. After the film has been exposed, it is laid on a sterile towel, and after exposures for die entire mouth have been made, the films are delivered to the dark room, the dark room operator taking precautions to safeguard himself. Between patients, everything that is touched by the operator's hands is wiped with a 40 per cent solution of alcohol and allowed to dry. Since this procedure has been instituted, there has not been even a suggestion of any kind of infection which could have been traced to X-ray technic. The foregoing precautions are more important when films are placed in the mouth direcly after operation, as the opportunity for infection is naturally greater.

PISTOL-GRIP NEEDLE FORCEPS FOR ABDOMINAL SURGERY.

The placing of sutures in the deeper regions of the abdominal cavity has always been a matter of especial difficulty in abdominal surgery. Owing to the prevailing straight construction of needle forceps, the operator's hand not only must be held at an uncomfortable angle, but also greatly obscures his vision. For surgical work in the nasal, aural and vaginal cavities, great advantage and perfect visual control is derived from the use of curved or angular instruments. Having this in mind, I have had constructed a pistolgrip needle forceps whose jaws are at an angle of thirty degrees to the handles, which permits a full unobstructed view of the operative field and gives perfect control of the needle even in the deeper and less accessible regions of the abdomen. In order to provide the power necessary to hold the needle securely, two levers are used, one acting on the other, thus greatly increasing the grasping force of the jaws.

ASEPSIS AND ANTISEPSIS IN OTOLOGY.

The application of the principles of asepsis in all their details has brought great progress in general surgery, in hygiene and in the particular branches of gynecology, obstetrics and ophthalmology; but in some other departments of medicine much is still to be done, before the ideal condition desired by the friends of asepsis will have been attained. Among these latter it seems to me that otology must be included, and that as regards it, the greatest number of scientists underrate the value and misunderstand the necessity for the strictest asepsis. Of course in large operations the instruments are boiled, the patient is cleaned, and as a rule the operator's hands are more or less carefully disinfected. But between this and a complete, consistent and thorough asepsis there is a wide difference. The principles of asepsis should be carried out in otology in the routine examinations of the ear, and especially

THE TECHNIQUE OF TENOTOMY OF THE OCULAR MUSCLES.

It is desirable that both patient and operator be in good physical condition. The surgeon, his assistant, patient, instruments, and operating room should all be rendered as aseptic as possible, because asepsis is the fundamental principle of modern surgery, which no ophthalmologist can afford to disregard, even when doing an ocular tenotomy. The operator's hands should be washed with pure soap and hot water, by the aid of a hand brush, so as to loosen all bacteria and other infectious materials lodged on the skin, attached to the hairs, embedded in the mouths of the oil or sweat glands or under the finger nails. This loosened debris is best removed by running hot water. The face, and beard (if the operator have one), are cleansed with scrupulous care. When dried, the hands are soaked in bichlorid solution, 1 to 1000. The assistant and patient cleanse themselves in a similar manner.

Scientific Serials

IN the Quarterly Journal of Science for October, three of the articles are continuations of papers which have appeared in previous numbers of the Journal. Mr Muogo Pontoa concludes his discussion of “Molecules, Ultimates, Aroms, and Waves.” Lieut. S. P. Oliver gives another paper “On Modern British Ordnance and Ammunition,” detailing the structure ot some recently manufactured ordnance; and from the ediior we have “Some further Experiments of Psychic Force.” After replying to adverse criticisms on his previous paper, Mr. Crookes details some fresh experiments which he considers to “contirm beyond doubt the conclusions at which he arrived in his former paper, namely the existence of a force associated in some measure not yet explained, with the human organisation, by which force increased weight is capable of being imparted to solid bodies without physical contact.” The experiments detailed were all performed in the presence of Mr. D. D. Home, or of a lady in whom this force is stated to be remarkably developed; the accordion is no longer employed, while in the balance experiments the operator's hands, instead of lying on the board attached to the balance, are placed in a vessel of water laid on the board. Mr, W. Mattieu Williams gives a useful abstract of the views advanced in his “Fuel of the Sun,” for the benefit of those who have not time to read the larger work. The author of an anonymous paper “On the recent Gun-cotton Explosion ” condemns the reaction against the use of gun-cotton, which has set in since the Stowmarket catastrophe, and attributes the explosion to culpable carelessness in the process of washing the free acid out of the cotton, and the extent of the disaster to the fact of the utterly needless stowage of large quantities of the manufactured article in the factory itself.