4i8 



tute, to fupply its place, in the compofition of gunpowder. We find 

 what an extenfive commerce, is opened to them, by their knowledge 

 of chymiftry, in the exportation of effences, perfumes, and all the 

 various productions of the alembic, or the furnace, for the ufe of ma- 

 nufafturcrs, for luxury, or for medicine. I mufl again obferve, on the 

 utility, of rendering the philofophic principles, of mechanical operati- 

 ons, familiar to the people, by details of the operations, in mecha- 

 nical arts, and of the procefs and operation, in preparing any valuable 

 or ufeful fubftance, whether as an ingredient, or auxiliary, in a manu- 

 fafture, or as in itfelf an objeft of commerce. 



The publication, which is called the Repofitory of Arts and 

 Manufaftures, and is chiefly compiled from the fpecifications of 

 various patents, may be attended with very confiderable advan- 

 tages. It contains inftruclive details, and important difcoveries, ia 

 various arts and manufaQures ; yet it fails of being as ufeful, as 

 fuch a publication might be, from a want of method and fcien- 

 tific arrangement. It is a confufed chaos of disjointed materials, 

 given, without feledion as to importance, or connexion as to fub- 

 jeft matter, from the fpecifications, as they happen to lie in the 

 office. It furnifhes, however, excellent materials for a regular me- 

 thodized work, on the details of trades and manufaftures. It 

 were much to be wiftied, that in order to diffufe a rational know- 

 ledge of the principles of trade and manufadures, and particu- 

 larly of the application of natural philofophy, in all its branches, 

 efpecially in chymiftry, to the manual arts, fome intelligent per- 

 fons were appointed, under the patronage of the Dublin Society, 

 to explain thefe topics, in public lectures, adapted to the capaci- 

 ties of common manufadurers, expreft in plain and familiar terms, 

 and illuftrated by experiments.* 



Such meafures woi>ld contribute particularly to the extenlion, 

 and improvement of the metallic manufadures, as well as of thofe 



* This has been executed, in some measure, since this Essay was wiitteD, in the Lec- 

 tures of the ingenious Mr. fJiggoni, 



