198 On Improvements in lleacking 



magnesia at one penny per lb., his proposal will receivs 

 attention. But considering my arguments against its 

 adoption as well founded, 1 have a right to maintain, thai 

 I was justifiable in using strong, though bv no means per- 

 sonal language, for the purpose of " deterring the manu- 

 facturer [bleacher] from acting upon it, by showing that it 

 was not only unnecessary, but absurd and ruinous for him 

 to attend to it. I understand that the Professor had an in- 

 terview with the trustees of the linen manufacture, — but I 

 have never heard that they have taken any notice of his 

 new proposal ; nor have conceived it necessary to issue any 

 new precautionary directions to the bleachers against the 

 use of the oxvniuriate of lime. 



I am accused of having erroneously stated as an assertion 

 of Sir Humphry's, that the salt of magnesia had entirely 

 superseded the salt of lime among the bleachers in Ireland. 

 I have to remark that this defender of Sir Humphry has 

 thought proper to slip in the word *' entirely," on his own 

 authority, to give perhaps the assertion a little more force 

 in my favour. But it is worth the rf;ader's while to remark 

 what is the answer to this. It is, that Mr. Davy has only 

 asserted that an enlightened individual has yet acted upon 

 his proposal. Thus, then, it is brought forward as a matter 

 of triumph, that almost two years after its birth, a single in- 

 dividual, not a bleacher but a calico-printer, has applied to 

 practice a proposal the professed object of which was to 

 benefit the staple manufacture of Ireland. 



To show, however, that I was not altogether unwarranted 

 in making the assertion, that Sir Humphry had adverted to 

 more than an individual having embraced his proposal, 

 I beg leave to introduce the following passage from the 

 Philosophical Magazine for March, p. 225, and from an 

 abstract of a lecture delivered by Sir Humphry at the Royal 

 Institution. It is in his 8th lecture: "A compound of 

 chlorine and lime is commonly en)ployed in bleaching, but 

 e\'en this injures the fabric of the linen. Mr. Davy has 

 found that a compound of chlorine and magnesia bleaches 

 without affecting the vegetable fibres, and on his sug- 

 gestion it has been used with success hy some manufacturers 

 in Ireland." Mr. Duffy, a gentleman engaged in a very 

 extensive calico-printing concern near Dublin, whose re- 

 spectability and scientific character from a long acquaint- 

 ance are wvll known to me, is brought forward as an evi- 

 dence in favour of the new proposal. I do not hesitate, 

 however, to state that, upon the subject of Mr. Duffy's 

 opinion, there is a mistake. I thought it my duty to call 



upon 



