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lished in 1754 his "list of the chief English authors (about thirty in 

 all) who have treated of minerals and metals," none had written a 

 treatise of metallurgy worthy of the name, though there were many 

 detached monographs of value and a few papers in the ' Philosophical 

 Transactions of the Royal Society.' In the period which elapsed, 

 nearly a century, between the publication of Cramer's book and the 

 time when Dr. Percy accepted the chair of metallurgy in the Royal 

 School of Mines and began to teach, the most noteworthy contribu- 

 tions to metallurgical literature were Bishop Watson's Essays. These 

 appeared in 1782, and are fragmentary, but, as Dr. Percy said, " are 

 elegantly and lucidly composed, and I never take them up but with 

 increasing pleasure." In 18G1 Dr. Percy published the first volume 

 of his treatise on ' Metallurgy,' which he dedicated " with sincere 

 respect and affectionate regard " to Faraday. This work, which he 

 calls the " task of his life," developed into a series of volumes con- 

 taining 3,500 octavo pages. It is on this treatise that his reputation 

 mainly rests, and we cannot doubt but that it will be enduring. The 

 writings of Pliny in the 1st century, of Geber in the 8th, and of 

 Agricola in the 16th, may still be read with profit side by side with 

 the modern work of Karsten, Gay-Lussac, Berzelius, Le Play, Plattner, 

 Deville, and Holley, and it is with these metallurgists that Percy 

 takes his place. His writings differ in many ways from those of his 

 predecessors in any country. He was forcibly impressed with the 

 fact that metallurgical problems demand for their successful investi- 

 gation the exercise of the highest analytical skill, and involve con- 

 siderations worthy of those who delight in transcendental inquiries. 

 He effectively quotes Reaumur's remark, "1 'utile bien considere a 

 toujours du curieux, et il est rare que le curieux bien suivi ne mene 

 pas a l'utile." 



The distinctive character of his metallurgical treatises arises from 

 the care with which he examined the relations of the metals to other 

 elements and to each other. While his predecessors unhesitatingly 

 accepted the statements of earlier writers or showed a tendency to 

 deduce from analogy what these relations would be, he made the proper- 

 ties of metallic compounds the subject of careful experiment and em- 

 bodied the results in his books, which form a record of great value, and 

 one that teems with suggestions for future investigators. The excel- 

 lence of the chemical portions of his books gives them great value as 

 works of reference quite apart from the accurate and elaborate de- 

 scriptions they contain of typical metallurgical processes. These were 

 in all cases prepared by the best men he could find, usually his own 

 students, who were actually engaged in conducting the operations they 

 describe. Such aid was always fully acknowledged. One remarkable 

 feature of these books is that almost every woodcut may be con- 

 sidered to be an accurate though small mechanical drawing, and it is 



