1862.] 287 



are added from time to time as they are completed. The preparation of 

 the second, or Alphabetical Index, is considerably advanced. For the 

 third, or Classified Index, the greater part of the titles are prepared, 

 but the arrangement of the classification has not yet been finally 

 decided upon. 



The number of Titles at present entered in the Catalogue amounts 

 to about 150,000 ; and there yet remain to be added from our own 

 library about 10,000 more ; besides such as may be added from other 

 sources. As was anticipated, numerous deficiencies in this department 

 of our Library were discovered in the course of the work. The Library 

 Committee has taken measures to have these made good. In some 

 instances imperfect series have been completed, and exchanges for new 

 series effected, on the application of the Foreign Secretary to the 

 several Societies by whom they are published ; considerable purchases 

 have also been made ; and by all these means the Library has been 

 largely increased in a department of essential importance to the in- 

 terests of all the sciences. The expense incurred in preparing the 

 Catalogue thus far has amounted to 56980. When the Manuscripts 

 of the three Indexes, Serial, Alphabetical, and Classified, are completed, 

 it is proposed to place them in the Library for the use of the Fellows 

 generally. In the course of the present Session it will be proper to 

 consider the question of extending the sphere of their utility more 

 widely by printing. It is scarcely possible to estimate too highly 

 the advantage of rendering such indexes easily and generally acces- 

 sible to persons engaged in scientific pursuits. 



I will now proceed with your permission to the duty especially 

 appropriate to the day, that of announcing the decision of the Council 

 in awarding four Medals in the present year, and of stating the grounds 

 on which those awards have been made. 



The Council have awarded the Copley Medal to Thomas Graham, 

 Esq., Master of the Mint, F.R.S., for three Memoirs on the Diffusion 

 of Liquids, published in the * Philosophical Transactions' for 1850 

 and 1851 ; for a Memoir on Osmotic Force in the 'Philosophical 

 Transactions' for 1854; and particularly for a paper on Liquid 

 Diffusion applied to Analysis, including a distinction of Compounds 

 into Colloids and Crystalloids, published in the ' Philosophical Trans- 

 actions ' for 1861. 



VOL. XII. Y 



