414- London Institution. — Scientific Books. 



resinous matter, and in order to free it from this it must be sublimed 

 very cautiously. 



This acid is obtained in the state of fine needles ; it is soluble in 

 water, in alcohol and in aether ; it differs from benzoic and cinnamic 

 acid in their being slightly soluble in water, whereas guaiaic acid is 

 perfectly soluble in it. 



M. Thierry has not yet analysed this acid, and he states that the 

 substance noticed by M. Righini as guaiaic acid in the Journal de 

 Chemie Medicate, 1836, is not truly this acid, but a resinous matter 

 which has been saponified by magnesia, and which is precipitated 

 when no longer held in solution by an alkali. — Journal de Phar- 

 macie, torn, xxvii. p. 382. 



LONDON INSTITUTION. 



The Lectures for the season will commence on Monday, Novem- 

 ber 8th, when Mr. Grove (whose appointment to the Chair of 

 Experimental Philosophy in this Institution we have already re- 

 corded) will deliver the first lecture of a Course on Magnetism. On 

 Thursday, November 11, Mr. Brayley will begin a Course on 

 Meteorology; and on Thursday, January, 6, 1842, Professor Grove 

 will commence another Course, the subject of which will be the 

 Physical Elements of the Ancient Philosophers. The series will also 

 include lectures on Manufactures, by Mr. E. Cowper, of King's 

 College ; on Rome, by Dr. Vaughan ; on Painting, by Mr. Haydon ; 

 on Music, by Mr. Gauntlett ; on the Fossil Remains of Extinct Ani- 

 mals, by Professor Ansted, of King's College ; on Numismatics, by 

 Mr. J. Williams; on America, by Mr. Buckingham ; and on Shak- 

 spere, by Mr. C. C. Clarke. Four Conversazioni will also be held, 

 on the evenings of Wednesdays, January 19, 1842, February 16, 

 March 16, and April 20. 



Mr. Brayley's Course on Meteorology will consist of Four Lec- 

 tures ; designed, principally, to illustrate the more recent observa- 

 tions and discoveries, and to review the present stale of our know- 

 ledge respecting Igneous Meteors and Meteorites. * 



SCIENTIFIC BOOKS. 



Conchologia Systematica, or complete System of Conchology : 

 in which the Lepades and Mollusca are described and classified ac- 

 cording to their Natural Organization and Habits ; illustrated with 

 300 highly finished Copper Plate Engravings, by Messrs. Sowerby, 

 containing above 1500 figures of Shells. By Lovell Reeve, 

 F.Z.S., Member of the Cuvierian Society of Paris, &c. 



The Undulatory Theory, as applied to the Dispersion of Light. 

 By the Rev. Baden Powell, M.A., F.R.S., F.G.S., Savilian Pro- 

 fessor in the University of Oxford. 



A Manual of Electricity, Magnetism and Meteorology. By 

 Dionysius Lardner, D.C.L., F.R.S., &c. 



A List of the Genera of Birds, with their Synonyma, and an 

 indication of the typical species of each genus, by George Robert 

 Gray. 2nd edit. 8vo. 



A New Process for purifying the Waters supplied to the Metro- 



