62 Dr. Thomson o» the Nature and Cure of Blindness. 



The value of each of the applications was precisely the same, viz., 

 five shillings for each lot ; or at the rate of £2 per acre. All the 

 articles were applied at the same time — on the 15th April, 1841, and 

 the grass cut and made into hay on tho following month of July. 



20th April, 1842,— 7%e President in the Chair, 



Dr. Stenhouse exhibited specimens of the Wood Coal of Germany, 

 — Divi-divi, &c. 



The following communications were read: — 



XVIII. — On the Nature and Cure of Blindness produced by Oil of 

 Vitriol. By Robert D. Thomson, M.D. 



At the meeting of the British Association which met at Glasgow in 

 1840, the author proposed an operation, by which he considered that 

 blindness, or opacity of the cornea, produced by the action of sulphuric 

 acid, might be remedied. This view was grounded on the following 

 considerations: — The basis of animal matter, according to the most 

 recent researches of chemists, appears to be a substance termed pro- 

 tein, consisting of C<o H31 N5 0,2, which can be readily prepared from 

 albumen, fibrin, &c., by solution in caustic alkali, and precipitation 

 by acetic acid. This substance appears to be a base, and combines 

 with acids. When sulphuric acid is brought in contact with it, a fine 

 white substance is formed, which may be obtained in the state of a 

 white powder by careful washing and drying. It may be conveniently 

 produced by triturating the crystalline lens of the eye in a mortar 

 along with sulphuric acid. This acid is termed sulpho-proteic, and its 

 formula is Pr + SO3. 



The conjunctiva, the membrane which covers the cornea, or tran- 

 sparent part of the eye, contains as its basis protein. If we, therefore, 

 bring sulphuric acid in contact with this membrane, sulpho-proteic 

 acid is formed, and opacity of the transparent cornea takes place. 

 This is the result when by accident, or intention, sulphuric acid falls 

 or is thrown upon the person. It was a case where this corrosive 

 liquid was thrown criminally at the head of a man that attracted the 

 author's attention to the subject. He found, by making a series of 

 experiments upon the eyes of dead animals, that when sulphuric acid 

 is applied to the cornea, a layer of sulpho-proteic acid is produced, 

 which may be removed by means of a sharp-edged knife ; and that, 

 even after dissecting off the first layer, a second application of the 

 acid will produce a new layer of sulpho-proteic, and which may be ex- 

 cised or torn off in a similar manner ; and in this way that the whole 

 of the cornea may be successively divided into a series of layers cor- 

 responding in some degree with the natural structure of that mem- 

 brane. This method presents, in short, an excellent mode of demon- 

 strating anatomically the layers of the cornea. Having found that 



