Linen and Cottbn Cloth. 193 



it, from the circumstances I shall immediately relate, and 

 from several well informed persons who attended the 

 lectures and compared their notes with mine. Conversa- 

 tions upon the doctrine, " that if a strong solution proves 

 detrimental a weak one must do so proporlionally," took 

 place immediately after the lecture, so as to impress it 

 strongly upon the memories of those concerned ; and I may 

 mention an incidental circumstance confirming fully the 

 accuracy of my statement, and which occurred during a 

 conversation that took place upon this subject at the last 

 meeting of the Kirwanian Society. A gentleiTian remark- 

 able for the tenaciousness of his memory, who attended Sir 

 Humphry's last course of lectures in Dublin, and who was 

 particularly attentive in collecting the general principles of 

 the science laid down by the lecturer, no sooner heard 

 what the point in dispute was, than he had a perfect recol- 

 lection of it, and accounted for the strong impression it 

 had made upon his mind, by remarking, that for some years 

 before he had been in the habit of using, by regular advice, 

 very dilute sulphuric acid as a tonic for his stomach ; and 

 it immediately struck him, up(m hearing the new doctrine, 

 that this practice must have been extremely imprudent, 

 since it is undeniable that undiluted sulphuric acid will 

 instantly destroy that important organ, and life itself. 



It is now said that the argument which the Professor 

 advanced in recommending his new project was not as I 

 have stated, but was as follows : " that bodies in their 

 nascent stale acted with more energy than when they had 

 been formed." It is very true that Sir Humphry did use these 

 words, so familiar to every student in the science; but it 

 was not in speaking of the oxymuriale of magnesia that 

 he used them, nor can they have any thing to do with it, 

 as to its superiority in bleaching over otlier compounds. 

 It was in speaking of the action of the oxygen of the water 

 upon the carbonaceous principle of the colouring matter, 

 before it perfectly assumes the gaseous form. 



It is really surprising how the person who signs his name 

 to a virulent attack upon my statement could gravely 

 thrust himself forward as an evidence upon this occasion ; 

 and, with an affectation of speakina; sarcasticallv of mo- 

 desty, adduce a quotation as if it were written by himself 

 at the time of the kcture, and this in ojiposition lo a num- 

 ber of gentlemen who were previously conversant with the 

 principles of the science, and who were exclusively em- 

 ployed in noting down every expermieni and observation 



Vol.40. No. 173. .Se/}/. 1812. N of 



