TO CORRESPONDENTS. 



Mr. Haworth's Third Decade of New Succulent Plants has been received, and 

 will appear in our next. 



Mr. S. Seward will receive a Communication from us. 



Mr. J. Lindley, on the Vegetable Physiology of M. du Petit-Thouars, in reply- 

 to Sir J. E. Smith, will appear in our next Number. 



Mr. Bywater's Description of a New Vertical Joint for Reflecting Telescopes, 

 has been received. 



The following communications have also been received : 



Mr. Paul Newton on the Duplication of the Cube ; and C. on the Solar Tables. 



Erratum.— In each of the Tables, in page 297 of our preceding Number, for 

 81, 22, 23, 24 Min., and 21, 22, 23, 24 Sec, read 30, 40, 50, 60 Min. and 30, 40, 

 50, 60 Sec. 



Shortly will be published, in 2 Vols. 8vo. 



PHARMACOLOGIA, Edition the Sixth. Corrected, Extended, and 

 Continued, in accordance with the new Pharmacopoeia of 1824, and 

 with the generally advanced state of Chemical Science.? 



By JOHN AYRTON PARIS, M.D. F.R.S. F.L.S. 

 Fellow of the Royal College of Physicians of London, &c. &c. &c. 

 In this Edition will be introduced a revolving scale, termed the Me- 

 dicinal Dynameter, which is capable of showing on mere inspection 

 the absolute and relative strength of the different Preparations of Medi- 

 cine, the composition of which being, at the same time, exhibited by a 

 combination of colours. 



London : printed and published by William Phillips, George Yard, 

 Lombard Street. 



Shortly will be published, in 1 Vol. 8vo. 

 Illustrated by numerous Engravings on Wood, 



THE ELEMENTS OF MEDICAL CHEMISTRY. Embracing 

 only those branches of Chemical Science which are calculated to 

 illustrate or explain the different objects of Medicine ; and to furnish a 

 Chemical Grammar to the Author's Pharmacologia. 



By JOHN AYRTON PARIS, M.D. F.R.S. F.L.S. 

 Fellow of the Royal College cf Physicians of London, &c. 

 " The objects of Science are so multiplied that it is high time to subdi- 

 vide them. Thus the numerous branches of an overgrown family in the 

 Patriarchal ages found it necessary to separate ; and the convenience of 

 the whole, and the strength and increase of each branch, were promoted 

 by the separation." — Priestley. 



London : printed and published by William Phillips, George Yard, 

 Lombard Street. 



A COMPANION TO ALL WORKS ON CHEMISTRY. 



This day is published in 8vo, with seventeen quarto copperplates, 

 price 16s. extra boards, 



AN EXPLANATORY DICTIONARY of the APPARATUS 

 and INSTRUMENTS employed in the various Operations of Phi- 

 losophical and Experimental Chemistry. 



By A PRACTICAL CHEMIST. 



Printed for Thomas Roys, Ludgate Hill ; and sold by Oliver and Boyd, 



Edinburgh, and all Booksellers. 



