112 SIXTH RKPORT — 1836. 



" In so for as I know, cataract in its early stages, when it may be 

 stopped or cured, has ne^-er been studied by medical men ; and even 

 when it is discovered, and exhibits itself in white opacity, the oculist 

 does not attempt to reunite the separating fibres, but waits with pa- 

 tience till the lens is ready to be couched or extracted. 



" Considering cataract, therefore, as a disease which arises from the 

 unhealthy secretion of the aqueous humour, I have no hesitation in say- 

 ing that it may be resisted in its early stages, and in proof of this I may 

 adduce the case of my own eye, in which the disease had made consi- 

 derable progress. One evening I happened to fix my eye on a very 

 bright light, and was surprised to see round the flame a series of brightly 

 coloured prismatic images, arranged symmetrically and in reference to 

 the septa to which the fibres of the lens are related. This phsenomenon 

 alarmed me greatly, as I had observed the very same images in looking 

 through the lenses of animals partially indurated, and in which the fibres 

 had begun to separate. These images became more distinct from day 

 to day, and lines of white light of an irregular triangular form afterwards 

 made their appearance. By stojiping out the bad parts of the lens by inter- 

 posing a small opake body sufficient to prevent the light from falling 

 upon it, the vision became perfect, and by placing an aperture of the 

 same size in the same position, so as to make the light fall only on the 

 diseased part of the lens, the vision entirely failed. 



" Being now quite aware of the nature and locality of the disease 

 though no opacity had taken place so as to appear externally, I 

 paid the greatest attention to diet and regimen, and abstained from 

 reading at night, and all exposure of the eyes to fatigue or strong 

 lights. These precautions did not at first produce any decided 

 change in the optical appearances occasioned by the disease ; but 

 in about eight months from its commencement I saw the coloured 

 images and the luminous streaks disappear in a moment, indicating in 

 the most unequivocal manner that the vacant space between the fibres 

 or laminae had been filled up with a fluid substance tninsmitted through 

 the capsule from the aqueous humour. These changes took place at 

 that period of life when the eye undergoes that change of condition 

 which requires the use of glasses, and I have no doubt that the incipient 

 separation of the laminae would have terminated in confirmed cataract 

 had it not been observed in time, and its progress arrested by the means 

 already mentioned. Since that time the eye, though exposed to the 

 hardest work, has preserved its strength, and is now as serviceable as it 

 had ever been. 



" If the cataract had made greater progress, and resisted the simple 

 treatment which was employed, I should not have hesitated to puncture 

 the cornea, in the expectation of changing the condition of the aqueous 

 humour by its evacuation, or even of injecting distilled water or an al- 

 buminous solution into the aqueous cavity." 



On the Nature and Origin of Cancerous and Tuberculous Diseases. By 

 R. Carmichael. 

 Mr. Carmichael having stated that the averaged mortality in these 



