66 Proceedings of Philosophical Societies. [July, 



light through the pupil. The respective advantages of these 

 methods have been long disputed, and each of them has been 

 alternately more in use than the other: even in the present day 

 .oculists are divided as to their respective merits, and prefer 

 ■cither one or the other, according to the ideas they have formed 

 of them, and the habit of using them which they have acquired. 

 The circumstance which has prejudiced some against the opera- 

 tion of depressing the cataract was the uncertainty as to what 

 became of the crystalline, and the fear that it should replace 

 itself, and again obstruct the pupil ; but it is now known by 

 the experiments of M. Scarpa, that it is either dissolved, or 

 absorbed, by the humours of the eye in a very short time, and 

 that every trace of it is speedily obliterated. 



M. Roux has read to the Academy a memoir on these two 

 methods, and their respective advantages ; he prefers the extrac- 

 tion, but he allows that it is not applicable to every case, and it 

 is only in these that he wishes the depression to be employed. 



RURAL ECONOMY. 



M. Yvart, being invited last year by the Minister of the 

 Interior to assist with his advice the proprietor of an estate in 

 - Auvergne in a large agricultural enterprize made on the ruins of 

 extinct volcanoes, immediately went thither, and has seized this 

 opportunity to study the system of rural economy adopted in the 

 neighbourhood of the Mont d'Or, and the Puy de Dome. 



He has furnished the Academy with the several objects whicli 

 struck his attention in this journey; such as the practice of 

 paring and burning the soil, the inconveniences ofecobuage, the 

 importance of natural and artificial meadows, the necessity of 

 ■destroying the prejudices that still exist on many points in 

 respect to the last, the cultivation of corn on steep slopes, that 

 of some economic plants proper to better the condition of the 

 inhabitants of mountainous tracts, the rearing, keeping, and 

 profits of cattle ; the means of supplying in many cases the use 

 of common salt in feeding cattle by acidulous mineral waters, 

 the acquisition, preparation, and employment, of manures and 

 dressings, the necessity of plantations, the precautions to be 

 taken in order to insure their success, the advantages and means 

 of establishing watered meadows. 



This last object having appeared to M. Yvart to merit the 

 being treated of in detail from the numerous notes which he had 

 collected in his different journeys through nearly the whole of 

 France, Italy, Switzerland, and England, he has endeavoured to 

 demonstrate in another work, which he has also submitted to 

 the Academy, the great importance of this kind of improvement 

 in our rural economy, and how much there remains for us to 

 perform in order to enjoy all the benefits of this practice. 



The Minister has recently caused the whole of the researches 



