taken subsequent to the administration of the fluid or of the fluid plus the phloridzin.

In the healthier organ there will be more polyuria and the urea and chlorids by liter will be diminished, but by quantity increased. The method permits one to ascertain with some surety the superactivity of which a kidney is capable, and to indicate the facility with which it is able to accommodate itself to increased excretory demands. By it may be shown which kidney functionates best, the approximate relationship in the functional capacity of each organ, but the test does not and cannot tell whether either or both organs are entirely normal or not.

Many criticisms of this method have been made, but it unquestionably stands as one of the most satisfactory of all the tests for renal permeability, especially since by it renal permeability to certain special substances, as to alcohol or other drugs, may be most readily shown.

CHAPTER III

THE CARE OF URETHRAL INSTRUMENTS. PREPARATION OF PATIENT AND SURGEON FOR OPERATION

THE CARE OF URETHRAL INSTRUMENTS

Casper has well stated that many aseptic conditions in the urinary tract may be rendered septic by uncleanly instrumentation. Zuckerkandl insists that catheterization should be regarded in the light of a surgical operation, and that preparations for carrying it out should be made with the same precaution as regards asepsis as are observed in performing operations on other portions of the body. It may be stated, also, that no amount of aseptic care regarding the hands of the operator, the sterilization of the instruments, or the preparation of the field of operation will render a trauma in the urethral tract caused by instrumentation harmless. The ease with which instrumentation can be carried out depends largely on the personality of the operator. Some men, even those of large experience are apparently regular bunglers in this respect. As regards cleanliness, sterilization of instruments, and preparation of the field of operation, however, personal equation is not a factor, since these procedures can be carried out by any operator who will give to the matter the time and patience required.

excess.

Sterilization should not, however, be carried to the point of In following the instructions laid down by some writers one is likely to produce irritation in the too strenuous effort to secure cleanliness. Illustrative of this overanxiety to obtain an aseptic field is the much-recommended practice, previous to inserting a catheter into the bladder, of washing out the anterior urethra with a solution of silver nitrate (one or two grains to the ounce) in the hope of rendering sterile any shreds that may remain in contact with the urethral walls. The too prolonged application of soap poultices for the purpose of loosening up the layers

of the superficial epithelium preparatory to operating will also prove irritating.

The following method for the care and sterilization of instruments and for the preparation of patients, in use in the City Hospital of New York, has stood the test of time and is easily followed.

Soft-rubber instruments, such as soft-rubber catheters, are boiled for five minutes in water to which washing-soda has been added, the proportion being a teaspoonful of soda to the gallon. They are then wrapped in sterilized gauze and kept in covered glass jars. Before being used they may be soaked for five minutes in 120 phenol solution, this to be washed off in a 4 per cent. boric-acid solution.

Not only the soft-rubber instruments, but also silk catheters and bougies may be boiled. The best way to do this is to wrap them in a piece of sterile gauze before boiling. When boiled, remove them still wrapped in the gauze with the fingers and place them in a cool solution. Boiling softens the lacquer that covers the silk instruments, and they are likely to suffer indentation if, while hot, another instrument is allowed to come in contact with them. This can be avoided by the use of the procedure mentioned above. Silk instruments may also be disinfected by immersing them for five minutes in a 1 : 20 phenol solution and then washing in boric acid 4 per cent., or they may be soaked in a 1 : 10 of 1 per cent. formaldehyd solution. It is recommended by many-and has come to be quite the general custom-that catheters be disinfected by preserving them in a glass jar having formaldehyd at the bottom, formaldehyd gas being generated; or that they be kept continually soaking in a 0.5 per cent. formaldehyd solution. Experience at the City Hospital seems to show that when either rubber or silk instruments are continually exposed to the fumes of formaldehyd vapor, or are immersed in a solution of formaldehyd of a strength of 0.5 per cent. or stronger, they soon become worthless. In private practice the writers have disinfected rubber and soft instruments by subjecting them to the action of formaldehyd vapor in the sterilizer described below, the vapor being generated by the heating. of a formaldehyd lozenge. After a few minutes the instrument is removed and wrapped in sterile gauze. When time will not permit,

or when the ordinary forms of sterilization are not available, a strong solution (2 to 4 per cent.) of formaldehyd may be used and immediately washed off. When frequent irrigations are to be made through a small olive-pointed gum silk catheter, a plan to be recommended in private practice is that of keeping each patient's instrument separate, thus reducing the danger of carrying infection by means of the catheter from one patient to another.

Steel instruments are sterilized by boiling them for five minutes

in a solution composed of a teaspoonful of soda to a gallon of water; they are then dried, wrapped in sterilized gauze, and placed in a glass jar with a cover; they may be then soaked in a 1:20 phenol solution for five minutes, being washed off, just before using, in a 4 per cent. boric-acid solution. For office practice, a small steam instrument-sterilizer works very well.

A sterilizer is used by the writers in which steam is generated; it is heated by means of an electric worm on the inside of the sterilizer, which is brought into immediate contact with the water.

The coil running from this apparatus is easily attached to the electric-light fixture, and the instrument has proved very practical. Care should be taken, however, that water is always present in the sterilizer.

Some advise the addition of a small amount of ammonium chlorid to the water in which instruments are to be boiled. A solution of mercury bichlorid (from 1:5000 to 1:3000) is a useful disinfectant, but has the disadvantage of turning metal instruments dark and of eroding their surfaces. A strong solution of formaldehyd in glycerin may also be used. The vapor of sulphu

rous acid has been employed as a disinfectant, but the simplest and most satisfactory method of sterilization is that accomplished by boiling water.

Cystoscopes may be disinfected by soaking them in 1: 20 phenol solution, care being taken not to wet the inside of the lenses; before using, the instrument may be washed off in a 4 per cent. boric-acid solution. Cystoscopes are best disinfected by allowing them to remain for a short time in the formaldehyd vapor generated in the formaldehyd sterilizer previously described.