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LXXIX. A Commumcal'ion relative to a Correspondence le- 

 tween Dr. Henry and Dr. Uee. 



To the Editor of' t fie Philosophical Magazine. 



SrB, — i.N page xiii of the Introduction to the Dictionary of 

 Chemistry lately published, I have alluded to Dr. Henry in terms 

 which have occasioned a private correspondence between that 

 gentleman and me, the result of which we are desirous of making 

 public in your Journal. 



In the beginning of August IS16, 1 transmitted to him an Essay 

 on Alkalimetry and Acidimetry, accompanied by a letter, in which 

 I begged him to favour me with his opinion of its merits, cau- 

 tioning him, meanwhile not to communicate its contents to any 

 person. In the Sth edition of his Elements, which appeared in 

 181S, he published a plan of alkalimetry and acidimetry modified 

 from that described in my Essay*. This struck me at the time 

 as an unwarranted use of my communication; and declining to 

 correspond with him on the subject, I resolved to seize the first 

 favourable opportunity to reclaim my rights. Under this feeling 

 I wrote the paragraph in the Introduction to the Dictionary. 



Dr. Henry thus writes me on the 12th of April 1S21, " I as- 

 sure you that I had not at the time of publishing my book, nor 

 can I now recall, the remembrance of any injunction of secrecy, 

 respecting your alkalimetcr; I conceived I had so expressed my- 

 self at page 512, vol. ii. of mv Elements, as imequivocallv to 

 give to you the credit of inventing an instrument on the principle 

 of directly, and without calculation, indicating the per cenlage 

 of alkali in any specimen ; and that I pretend to nothing more 

 than the modification of your method which is described in mv 

 book," 



Under these circumstances, I am satisfied that Dr. Henry had 

 no intention to appropriate to himself the credit of my invention; 

 but I sincerely regret that, before pronmlgating the modification 

 of my method, he had not consulted me on the sulgect. This 

 would have prevented all chance of misunderstanding between 

 me and Dr. Henry, whose accomplishments as a gentleman and 

 a chemist, I have been accustomed to admire. The readers of 

 the Dictionary will perceive under the articles Calculf, Coai.- 



* " It has been very properly objected to it '[tlie alkalimetei- of Descroi- 

 silles] by Dr. Lire of Glasgow, (in an Essay on Alkaliiuetrv, which he was so 

 good, about two years ago, as to comnmnicate to me in manuscript, and which 

 I believe he has not yet published,) t!iat these degrees, being entirely arbi- 

 tral y, do not denote the value of alkalis in language universally intelligible; 

 and he has proposed an instrument which shall at once, and without calcu- 

 lation, declare the true proportion of alkali in 100 parts of any specimen. 

 The principal deviation in tlic fuUowiig rules from the method of Dr. Ure, 

 is," &c. Stc. 



GAS^ 



