132 VETEIilNAEY OPHTHALMOLOGY. 



iible, i.e., in the very obscure and slight cases, it was of 

 little use. It is still useful in determiiiing the presence 

 •or absence of the lens, and depends upon the fact that 

 the surfaces of tlie cornea and lens reflect images and 

 consists of the following maneuvr'es : Hold a candle, 

 lighted, ,_efore an eye in a darkened room, and you will 

 observe three distinct images — the anterior, bright, erect 

 and distinct from the anterior surface of the cornea; an 

 intermediate, slight, smaller, inverted, and fairly dis- 

 tinct from the lens^ posterior capsule, which is con- 

 ■cave ; and a posterior, indistinct and erect from the 

 surface of the lens' anterior capsule. To return to 

 •oblique illumination, and this is of extreme applica- 

 bility. While being very easy, the veriest novice hav- 

 ing it at his command, it is decidedly thorough, one 

 Ijeing enabled by its mediation to discern the slightest 

 opacities and strise of incipient cataract, etc. For 'this 

 test, need but a 2i inch lens and a candle flame. To 

 Ibe thorough, the use of cocaine, atropine, or scopo- 

 lamine is necessary. Have the candle placed on one 

 side of the head and concentrate its rays by means 

 of the lens so as to focus upon the eye, and then the 

 cornea, the pupil, the iris and the lens may be very 

 thoroughly studied. For the examination of the 

 anterior parts and chamber, the lens is sufiicient, 

 but there it ends and the ophthalmoscope comes into 

 play. If we take a small box and punch a hole in the 

 top, through which we send a pencil of light liy means 



