4 A Tribute to t/ie Memory of 



of a respectable apothecary in Manchester ; where he continued, 

 for nearly half a century, to be employed in medical attendance 

 for the most part on the more opulent inhabitants of the town 

 and neighbourhood. 



Soon after Mr. Henry's settlement in Manchester, tlie late 

 Dr. Percival removed to the same town from Warrington. That 

 eminent physician was early inspired with the same ardent zeal 

 for the cultivation of professional and general knowledge, which 

 afterwards so much distinguished him. Between Dr. Percival 

 and the subject of this memoir, congeniality of taste and pursuits 

 led to a frequent intercourse ; and the moral qualities of both 

 cemented their connexion into a friendship which continued, 

 without interruption, until it was terminated by the death of Dr. 

 Percival, in 1804. It was about the same early period, that he 

 -formed an acquaintance with that excellent man, and upright 

 magistrate, the late Mr. Bayley, of Hope-Hall ,;and much of the 

 happiness of his future life was owing to the mutual esteem and 

 confidence, and to the frequent intercourse, which continued to 

 exist between them for more than thirty years*. 



During his apprenticeship, Mr. Henry had manifested a de- 

 cided taste for chemical pursuits, and had availed himself of all 

 the means in his power, limited as indeed they were, to become 

 experimentally acquainted with that science. This taste he con- 

 tinued to indulge after his settlement in life ; and, after having 

 made himself sufficiently master of what was ascertained in that 

 department of knowledge, he felt an ambition to extend its 

 boundaries. In the year 1771, he communicated to the Royal 

 College of Physicians of London, " An Improved Method of 

 Preparing Magnesia Alba," which was published in the second 

 volume of their Transactions. Two years afterwards it was re- 

 printed, along with essays on other subjects, in a separate 

 volume, which was dedicated by Mr. Henry to his friend Dr. 

 Percival. 



The calcination of magnesia had, at that time, been practised 



♦ An interesting biographical sketch of Mr. Bayley, written by Dr. Per- 

 ^■ival, appeared in one of the volumes of the Moyithly Magazine for the year 

 180S. 



