DR. E. SCHUNCK ON ANTHIIAFLAVIC ACID. 227 



the raised parts was carved out by any mechanical agency 

 on a frozen or a freezing surface. That produces the 

 forms spoken of (if we are judging rightly) on rather dry 

 ground. I assume that the origin is not quite the same. 

 But the second action was considered to be that of the 

 growing plant; and that is probably the degree required 

 to form the peat-bog forms. One may notice that, from 

 the earliest commencement, the plants found in them 

 seem to grow in tufts by preference, either from a defect 

 in the ground having few spots capable of giving nutriment 

 or from a defect in the plants, there being few that take 

 firm root. When once the beginning is formed, the growth 

 is easily accounted for in the same manner. 



I conclude that the results seen on the fields in Iceland 

 are not identical in kind, and are only somewhat similar 

 in appearance. 



XXVIII. On Anthraflavic Acid, a Yellow Colouring -mat- 

 ter accompanying Artificial Alizarine. By Edward 

 Schunck, Ph.D., F.R.S., F.C.S. 



Read March 7th, 1871, 



The artificial formation of alizarine is a process of very 

 great interest to the scientific chemist as affording the 

 first instance of the production of a natural colouring- 

 matter by artificial means, and also to the technologist, 

 since it is chiefly to alizarine that madder owes its valu- 

 able dyeing properties. The process itself, as described 

 by its discoverers (Graebe and Liebermann), seems ex- 

 ceedingly simple. It consists essentially in the conver- 

 sion of the hydrocarbon anthracene, C I4 H I0 , into alizarine, 

 C, 4 H 8 4 . Nevertheless the product obtained on a large 



q2 



