to the cultivation of the Woad Plant. 61 



Formerly there was a mysteriousness in the pro cess. 

 which, for a long time, excluded all attempts at inves- 

 tigation. Those who practiced the art, made it a point 

 to keep as important secrets, whatever they knew, and 

 like manufacturers of glass, suffered no inspection of 

 their labours, lest they should be robbed of an imaginary 

 treasure. There were no means within their power of 

 detecting the causes of failure in the preparation of their 

 vats, for they were ignorant of the chemical effects of the 

 different ingredients used. They merely knew from 

 practice or tradition that a certain combination of materi- 

 als, made a red, blue, yellow or green dye, and if from 

 an injudicious admixture, the anticipated result did not 

 take place, they merely said they had " bad luck" 



Long custom had created prejudices which forbid in- 

 struction, and like many individuals of every mechanic 

 art, the dyers laid it down as an axiom, that nothing use- 

 ful could be learned from books, or instruction commu- 

 nicated by individuals who had not served an appren- 

 ticeship and laboured in the same vocation. 



The vast strides which have been made in knowledge 

 during the last fifty years, have not been confined to the 

 schools of the Literati, or only known to the secluded 

 philosopher. 



Useful discoveries in the arts, instead of merely giving 

 eclat to the laborious investigator, and patient experimen- 

 talist, have been extensively disseminated. 



The perfection of European manufactures is attributa- 

 ble to the march of chymical investigation. 



The superior manufactures of Painter's colours, earth- 

 en-ware and porcelain, soap, medicinal preparations, the 

 working of metals, the art of dying and distilling and 



