Cystophotographic atlas / by Max Nitze ; translated by E. Michels.

  • Maximilian Nitze
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Cystophotographic atlas / by Max Nitze ; translated by E. Michels. Source: Wellcome Collection.

    12/60 (page 4)
    until the next opening is opposite the tube, and it is then again ascer- tained whether the object is in proper focus. Thus it is possible to obtain a series of exposures either of one or more objects on the same plate. The dimensions of the real image in the cystoscope are 3 mm; those of the unenlarged photographs are of course the same. The manipulation of the instrument is a comparatively simple matter; the sensitive plate is brought into position, the lid screwed on, the ocular piece adjusted and the instrument is passed into the bladder like an or- dinary cystoscope. Any part of the wall of the bladder may be easily brought in focus. When the selected spot is found the instrument is fixed, the current interrupted, the ocular piece drawn back and the lamp allowed to burn as bright as possible for a short time. The current is then again cut off and the cover of the camera rotated to the right until the arrest of the spring marks the exposure of another part of the plate; if several exposures of the focussed part are required, the lamp is again made as strongly incondenscent as possible for a short time; otherwise if it is re- quired to photograph another part, after cutting off the current and read- justment of the ocular the next selected part is brought into focus and photographed as before. In this way ten negatives may be obtained either of one or of different parts of the bladder; the time of exposure may also be varied at pleasure. As it is well known that even in ordinary photo- graphic work a certain percentage of the negatives obtained are indifferent or useless, it is not surprising that under the increased difficulties attend- ing cystoscopic photography only a part of the negatives give satisfaction. It is therefore the more important to be enabled to take a number of negatives of the same object in a short time as the probabilities are thus increased of being able to select some free from defects. The photographic plates required for the cystoscope are as sensitive as possible and at the same time possessing a finely granulated surface. Unfortunately the one requirement is to some extent antagonistic to the other; the highest degree of sensitiveness and the finest granulation are seldom found in the same plates; the most sensitive plates are generally somewhat coarsely granulated and the finely granulated ones are not very sensitive. The importance of great sensitiveness is evident; the shorter the time of exposure the less troublesome is the whole process to the patient. The plates now in use only require an exposure of 3 to 10 seconds, which is certainly satisfactory. The question of granulation is a more complicated one. By exami- nation of a glass-negative with the low power of the microscope it is seen that the picture is formed by a great number of more or less uniform granules of metallic silver which if not too closely packed appear as small