422 On Bleaching by Oxymuriatic Acid. (Dec. 
bleaching by oxymuriatic acid into this country, which, though 
correct in the main, is not altogether so. It resembles, indeed, so 
closely, in several respects, a statement published some years ago 
in Dr. Rees’s Cyclopedia, that it is probable the historical informa- 
tion of both was derived from the same source. You will, there- 
fore, oblige me, if you consider the subject of sufficient importance, 
by admitting into your Journal the substance of a representation, 
which I addressed several years ago, to the Rev. Dr. Rees, in 
behalf of the claims of a person in whose reputation I may natu- 
rally be supposed to feel some interest.* But, independently of 
this interest, it does appear to me, that the public ought to be set 
right respecting the real history of this invention. The credit 
which a man of science derives from contributing to the improve- 
ment of the useful arts, is often (as in this case) the only reward he 
receives; and it is the duty of the historian of those arts, first to 
make himself thoroughly master of the facts, and then to detail 
them with fairness and impartiality, 
I have chosen this time for bringing the matter before the public, 
because_all the parties concerned are still living, some of them at 
a very advanced age, and may readily be called upon for farther 
evidence, if it should be thought necessary. 
I am, dear Sir, yours very truly, 
Wo. Henry. 
(To the Rev. A. Rees, D.D. F.R.S. &c.) 
REV. SIR, Dec, 1809, 
Observing that the early volumes of your Cyclopedia are about 
to be reprinted, I am induced to fulfil an intention, which I have 
long-entertained, of addressing a few lines to you respecting the 
article BLEAcHING, published in vol. iv. part 2, Ist edition. The 
writer of that article, in assigning to different persons their shares 
of merit, in the introduction of the mode of bleaching by oxy- 
muriatic acid and its compounds, has made a distribution, which 
is very far from being an equitable one. 
Of the part which was taken by Mr. Watt of Birmingham, in 
the application of Berthollet’s important discovery, far too little is 
said ; and of Mr. Henry’s share in the improvement not the small- 
est notice is taken, though it could not fail to be known to the 
writer of the article, who, at that period, was himself engaged in 
this town in pursuit of the same object, and was in habits of occa- 
sionally communicating with Mr. Henry on the subject. The 
truth is, that next to Mr. Watt, Mr. Henry was at least equally 
early with any other person in applying the discovery to practice. 
In proof of this | might appeal to the general notoriety of the fact 
- in this town and neighbourhood: but I depend chiefly for its esta- 
blishment, on a number of letters from Mr. Watt to Mr. Henry, 
written in the year 1788, which are now before me, They form 
* The person alluded to is Mr. Thomas Henry, F,R,S., President of the 
Literary and Philosophical Society of Maachester, 
