PREFACE TO THE FOURTH SERIES. 



In commencing with the year 1851 a New Series of 

 The Philosophical Magazine, the Editors are induced 

 to hope that they may refer to the progress and conduct 

 of the work through its existence of more than half a 

 centmy. Having been begun by Dr. Alexander Tilloch 

 in 1798, with a view to the promotion of science, it has 

 ever been the object both of its original Editor and of 

 his successors, to record all the great discoveries made, 

 since the sera of its commencement, as they could be col- 

 lected from the most authentic sources foreign as well as 

 domestic. 



In addition to the copious supply which these afford, 

 the numerous Original Communications with which the 

 Philosophical Magazine has been honoured by the most 

 eminent Cultivators of Science of the present day may be 

 stated as giving the work a just claim to general sup- 

 port. As the representative also of the several Jom-nals* 

 which have from time to time merged in this, it has 

 long occupied in all parts of the world a rank similar to 

 that held by the Annales de Chimie et de PJii/siqiie, by 

 PoggendorflP's Annalen, and others ; Avhilst from its ex- 

 tensive foreign cu'culation it is the principal vehicle of 

 communication between the Philosophers of our own and 

 of foreign coimtries, as is shown by the constant reference 

 to its pages, and the frequent translation of its Ai'ticles, 

 in foreign scientific works. 



The important duty of making known in this country 



* Nicliolson's Journal : The Annals of Philosophy : The Journal 

 of Science. 



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