1865.] 225 [Wood, 



While thus engaged in teaching chemistry, both as a writer and 

 lecturer, he did not neglect his professional business. To his private 

 practice, which came very slowly, and never in a degree equivalent 

 to his merits, were added, for several years, the oiEcial duties of in- 

 specting recruits for the United States army, and of attending mili- 

 tary officers who might happen to require medical aid when stationed 

 in Philadelphia. He was, moreover, for a considerable time, physi- 

 cian both to the old Walnut Street Prison and to the new Peniten- 

 tiary at Cherry Hill, to the former of which he was appointed in 

 1824, and to the latter in 1829. 



Besides these avocations, which yielded him more or less income, 

 he was for a period of six years, from 1826 to 1832, engaged, with 

 several others, in gratuitously conducting the North American Medi- 

 cal and Surgical Journal, one of the best medical periodicals then 

 existing, which occupied much of his time and thoughts; and in the 

 year 1829, he entered upon another course of unpaid labor, on the 

 part of the College of Physicians of this city, in revising the United 

 States Pharmacopoeia, which was repeated every ten years as long as 

 he lived. 



Nor did he confine himself, at this period of his history, exclu- 

 sively to chemical and professional labors. His situation, already 

 referred to, of physician to the two State Prisons, the Walnut Street 

 Prison, conducted on the old collective principle, and that at Cherry 

 Hill, on the new Pennsylvania system of solitary confinement, not 

 only suggested inquiry into the general subject of penitentiary disci- 

 pline, but gave him excellent opportunities of comparing the two 

 systems, and of determining their relative value. With one of his 

 thoughtful turn of mind, such inquiries almost necessarily matured 

 into decided opinions, which deserve great weight, in consequence 

 not only of his opportunities, but also of his excellent judgment. 

 His views on the subject were given in two letters to Roberts Vaux, 

 well known as a zealous advocate of the modern plan, which were 

 published in the third and sixth volumes of Hazard's Register, and 

 also separately in a pamphlet form. 



Of these two letters, the first presented the evils of the collective 

 or gregarious system, as he had observed it in operation in the old 

 prison, and those of the solitary system, as alleged by its opponents, 

 with comments of his own, which lead necessarily to the conclusion 

 that the latter is far preferable to the former in most points, and 

 scarcely inferior in a single one. The second letter gives the results 



