ERRATA AND ADDENDA.

P. 93, line 3 from bottom, for “ saleratus ” read “ bicarbonate of soda.”

P. 226, line 8, for “ lime ” read “ iron.”

P. 239. The formula of alizarin is now considered to be C14H8O4.

P. 438, line 14 from bottom, read “ a perfedlly definite nitrogenous principle.”,, line 6 from bottom, for “chemistry” read “ compounds.”

P. 439, line 22 from bottom, erase “ and chlorine.”

P. 440, line 6 from bottom, for 11 sulphuric acid ” read “ sulphurous acid.”

P. 447, line 24, for “ found” read “ formed.”

,, line 10 from bottom read “ in certain animal secretions, such asurine, not merely pathologically, but as a result of ordinarymetamorphosis of tissue (see Schunck on the Occurrence of IndigoBlue in Urine).”

P. 468, line 7 from bottom read “ enluminage.”

P. 470, line 19 from bottom read “ that trials in pradtice on the large scalediffer from.”

P. 472,line 15 from bottom, for “adtive” read “process.”

P. 476, note, erase “ by porosity through the fibre.”

P. 534, line 3, after “ cotton-yarn” insert “ it.”

P. 539, line 17,/or “ nitric acid” read “nitrate of iron.”

P. 553, line 10 from bottom, erase “throws.”

P. 651, line 20, for “ chiefly ” read “ sometimes.”

„ line 26, for “ woven ” read “ unwoven.”

P. 654, line 6 from bottom :—In an improved machine there are two rollersfixed over the beck. The goods run over one roller, through the liquor, andon the other roller. By reversing the handle the pieces are alternately coiledand uncoiled round each roller.

P. 665 (Detedtion of Reds)To distinguish saffranin from magenta boil theswatch in alcohol. If it is magenta the solution will appear crimson andtransparent, both by refledted and by transmitted light; whilst saffranin solutionis rose-colour and transparent by transmitted light, but appears turbid, opaque,and scarlet by refledted light. Warm water containing 5 per cent of soapbecomes coloured if a swatch dyed with magenta is steeped in it, but remainscolourless if the dye be saffranin. If a swatch is steeped in water acidulatedwith hydrochloric acid, along with a piece of zinc, it will soon be decolourisedif the dye is magenta ; saffranin remains unchanged for some time, and thenturns a bright yellow.