The endoscope as an aid in the diagnosis and treatment of disease / by Francis Richard Cruise.

  • Cruise, Francis Richard, 1834-1912.
Date:
[1865]
Catalogue details

Licence: Public Domain Mark

Credit: The endoscope as an aid in the diagnosis and treatment of disease / by Francis Richard Cruise. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    flame, partakes of the kiminosity of the whole depth of the flame, inasmuch as light permits the passage of light through itself with- out loss. It may be possible, too, that the more perfect combustion of the edge, due to freer contact with the air, augments its brilliancy- In my instrument I usually dispense with the reflector, because it is rarely, if ever, required. For such cases as may Fig. 4. need it I have had a special reflecting chimney con- structed, which is represented, in section, by Fig. 4. It consists of a copper tube, shaped like an ordinary draught chimney, having, at one side, at the level of the flame, a small window of parallel plate glass (represented on the right hand in the woodcut), and on the side opposite thereto, a flat silver reflector so an-anged that when the flame is lighting it can be pushed close up to it. While in use, the chimney is so placed that the window des- tined to transmit the light is opposite to one edge of the flame, while the reflector lies close up to the other. Two good effects are obtained by this apparatus. In the first place the light is reduplicated by the mirror; and, moreover, the rays do not suffer in passing through the plate glass window the dispersion which Is inevitable with the common round glass chimney. The precise amount of increase of light depends on circum- stances ; at best, it does not exceed one half with a single mirror, as fully that quantity is lost by absorption in reflection. Were it needful, the illumination might be increased almost indefinitely by surrounding the flame with a series of concave reflectors, as repre- sented in Fig. 5, having theu' foci in a point in the flame; however, in my endoscope, as at present used, I think there is ample light, and it is very desirable to avoid complexity as much as possible. One serious objection to reflectors is the diflficulty of keeping them clean enough to be effective. The best material of which to make them is silver, somewhat hardened by alloy; it is easily polished, bears heat well, and when tarnished may be readily brightened with a bit of soft chamois leather. I avoid smutching