NEW MODE of W ASH IN G.-Messrs-TWELVETREE8 having devoted considerable atten-lmpiovem«n^ of their WASHING PREPARA* succeeded in producing an entirely new article* which Is effectual in its results, and which is warranted not to injure or corrode the finest fabric, as the following important testimony vriU show:— r« t v ° lipndou, 24, Bloomsbury-tquare, 25th May, 18*9.1 have analyzed Twelvetrees’ Improved Washing Prepara-tton. aud hereby certify that It Is perfectly eafe, end not iS the If? Ik / coriode or injure Linens or CotionB washed with it by the Laundress. It is a very effectual detergent, and coincides In this respect with soap.“ANDREW URE, M.D., F.R.8., c. c„ Professor of Chemistry, and Analytical Chemist.