72 
WANDERINGS IN CHINA. 
Chap. IV. 
subject are well known. In a paper read by him before 
the Chemical Society, and published in its ^Memoirs 
and Proceedings/ he says, — 
" Mr. Fortune has forwarded from the north of China, 
for the Industrial Exhibition, specimens of these mate- 
rials (tea dyes), which, from their appearance, there can 
be no hesitation in stating are fibrous gypsum (calcined), 
turmeric-root, and Prussian blue ; the latter of a bright 
pale tint, most likely from admixture with alumina or 
porcelain-clay, which admixture may account for the 
alumina and silica found as stated in my previous 
paper, and the presence of which was then attributed 
possibly to the employment of kaolin or agalmatolite." 
