On Cure of Cataract. SOS 



tated by caustic potass, so that the whole of the copper was 

 not separated. The mucilaginous green precipitate was 

 washed on a filter with boiling water; but since the water 

 passed through it too slowly, after the filtration had con- 

 tinued two days, il was dried, powdered, and then boiled 

 with spirit of wine. The salt was again well dried, and 

 became of a yellow i)rown colour. I introduced five gramme* 

 of it into nitric acid, in which it was very slowly dissolve<l: 

 it was then precipitated by nitrate of silver. The luni 

 cornea, when fused, weio;hed 3"3 gr., indicating -617 ot" 

 muriatic acid. The liquid was boiled with mercury, in 

 order to separate the oxide of silver, then evaporated in a 

 cruciijle of pUtina, and ignited ; it afforded 3*680 gr. of black 

 oxide of copper. The suhsait consists therefore of 

 Muriatic acid 14-36 100 



Oxide of copper 85*64 59(i 



Consequentlv 100 [.arts of muriatic acid are combined, 

 in this salt, with four times as much of the base a.i in the 

 neutral salt ; for l'18*7 X4 = 594-S, which differs only by 

 1*2 from the rusult of the experiment. 

 [To be continued.] 



XXXI r. On the Bsmoval of Impediments to the Acquire^ 

 ment if f^ision by Persons cured oj Cataract. 



To Mr. Tilloch. 



Sir, — In a woilc rccenlly published, on Diseases of the 

 Kve, by Mr. Adams, Oculist Elxtraordinary to His Royal 

 Highness the Pnnce !?• gent, and late Surgeon to the West 

 of bliigland Infirmary for curing Diseases of the Eve, insti- 

 tnled at F.xcicr, I have perused with nuich satisfactlrm 

 some original observations on the causes, and ingenious 

 hints for ihc removal, of the impediments to the acquire- 

 ment of vision by persons cured of cataract \\ho were borrt 

 blind wi'h them. This form of the disease appears to be 

 tuuch more frequent than is generally supposed, if \ffi 

 may judge from the large mimber of persons (upwards cf 

 seventy) Mr. Adams mentions to have successfully ope- 

 rated on. The benefit however to be derived by the patient 

 even after the most successful operation, according to Mr. 

 Adams's account, wfio seems to have bestowed great atten- 

 tion to this subject, depends un their alter education. This 

 then naist be considered an object of tlie highest Impon- 

 anec ; and as 1 know of no oiie except himself who lu? 

 hitherto sugiiested any plan for the purpose, I inclose a 



copy 



