264 KEPORT— 1895. 



exposing space certain important groups of colouring matters had to 

 remain unrepresented, e.g., the Congo Reds, itc. These have now been 

 examined, together with additional coal-tar colouring matters recently- 

 introduced, also certain Indian dyestufFs. With some few exceptions, 

 therefore, all the available red, orange, and yellow colours, as applied to 

 wool and silk, have now been exposed. 



The general method of preparing the dyed patterns, and the manner 

 of exposing them under glass, with free access of air and moisture, were 

 the same as already adopted. 



The thanks of the Committee are again due to James A. Hirst, Esq., 

 in whose grounds the patterns were exposed at Adel, near Leeds. 



Each dyed pattern was divided into six pieces, one of which was 

 protected from the action of light, while the others were exposed for 

 different periods of time. These ' periods of exposure ' were made equivalent 

 to those adopted in previous years by exposing, along with the patterns, 

 special series of ' standards,' dyed with the same colouring matters as were 

 then selected for this purpose. The standards were allowed to fade to the 

 same extent as those which marked off the ' fading period ' in previous years, 

 before being renewed or removing a set of dyed patterns from the action 

 ■ of light. The patterns exposed during the past year are therefore 

 comparable, in respect of the amount of fading which they have ex- 

 pei'ienced, with the dyes already reported upon. 



The patterns were all put out for exposure on June 20, 1894, cer- 

 tain sets being subsequently removed on the following dates : — July 14, 

 August 20, September 22, 1894 ; April 13, July 16, 1895. Of these five 

 'periods of exposure' thus marked off, periods 1, 2, 3 were equivalent to 

 each other in fading power, whereas periods 4 and 5 were each equivalent 

 to four of the first period in this respect ; hence fi%'e patterns of each 

 colour have been submitted respectively to an amount of fading equal 

 to 1, 2, 3, 7, and 11 times that of the first 'fading period' selected — viz. 

 June 20 to July 14, 1894. 



The dyed and faded patterns have again been entered in pattern-card 

 books in such a manner that they can be readily compared with each other. 



The following tables give the general result of the exposure experi- 

 ments made during the year 1894-95, the colours being divided, according 

 to their behaviour towards light, into the following five classes : very 

 fugitive, fugitive, moderately fast, fast, very fast. 



The initial numbers refer to the order of the patterns in the pattern- 

 books. The S. and J. numbers refer to Schultz and Julius's ' Tabel- 

 larische Uebersicht der kiinstlichen organischen Farbstoffen.' 



In the case of colouring matters requiring mordants, the particular 

 mordant employed is indicated in brackets after the name of the dye- 

 stuff. 



EED COLOURING MATTERS. 



Class I. Very Fugitive Colours. (Wool.) 



The colours of this class have faded so rapidly that at the end of the 

 first 'fading period' (June 20 to July 14, 1894) only a very faint colour 

 remains, and at the end of the fifth period (one year) all traces of the 

 original colour have disappeared, the woollen cloth being either quite white 

 or merely of a faint tint which ^aiies according to the colour of the origi- 

 nal pattern. 



