ADVERTISEMENT. 



THE Patrons and Fn\nds of the Philofophical Journal ari 

 refpeclfully informed, that this work xcill in future conjift of fix 

 fheets of matter inftead of Jive in each number^ together with a 

 fupplementary number to each volume; and that the plates will 

 be fo managed as to contain a larger number of fubjecls executed, 

 in the befl fiile. Thefc improvements, though attended with ad- 

 ditional expence, are fitch as the Editor has thought it his duty to> 

 adopt ; in order that the very extenfive communications with which 

 the Journal has been honored, might not prevent him from giving 

 all the foreign difcoveries and fuch other general intelligence as 

 the nature of the plan demands. It will cajily be feeii that the, 

 additional copy will by this 'means amount to one half more than 

 the former quantity ; and it is unnecefjary to point out the great 

 advantages which muft refult from fuch an addition. The Editor 

 takes this occajion to repeat his acknowledgments for the encou- 

 ragement which has been given to his exertions, particularly 

 within the lafi twelve months, in which the [ale has nearly 

 doubled,* The quantity of original matter continues to increafe r 

 and amounts to more than half of the whole work. Great part 

 vf the remainder confifts in foreign articles never before publijhed 

 in this country, together with fame extracts and abridgments from 

 our beft academical tranfaclions. The whole publication may 

 therefore be conjidered as original, jince it is never made up by 

 extracts from the periodical works of this country, which, on the 

 contrary, very frequently copy from its contents. 



* It has been necefTary to reprint a confiderable part of the former volumes 

 in order to make complete fets, which may now be bad, or any {ingle numbers 

 or volumes, from the commencement* 



