212. A Tribute to the Memory of 
afriend, in a letter relating to the intended 
publication, which is still preserved as a part 
of his correspondence. Before carrying this 
suggestion into effect, he thought it proper to 
consult Sir John Pringle, Sir Clifton Win- 
tringham, Dr. Warren, and some other lead- 
ing members of the College of Physicians, as 
to their opinion of the propriety of the mea- 
sure ; and he did not adopt it, until those gen- 
tlemen had each declared it to be not more 
advisable on his own account, than on that of 
the public. 
Soon after the publication of the small vo- 
lume of Essays, Mr. Henry found himself in- 
volved in a controversy, arising out of some 
remarks in the appendix, respecting which, 
as the subject was of temporary interest, itis 
unnecessary to enter mto particulars. It. is 
sufficient to state that the accuracy of some 
of his experiments, which had been cailed in 
question, was confirmed by the concurrent 
testimony of Dr. Percival and Dr. Akin; 
and that the chemical properties, first ascer- 
tained by him to belong to pure magnesia, were 
considered, by Bergman and by Macquer, as 
worthy of being incorporated into their res- 
pective histories of that earth. 
It was probably in consequence of the pub- 
lication of these enquiries, that Mr. Henry 
