86 



fairly concluded that the thickness of layers of stalagmite 

 cannot be used as an argument in support of the remote age 

 of the strata below. At the rate of a quarter of an inch per 

 annum 20 feet of stalagmite might be formed in 1000 years. 



"On Methyl-alizarine and Ethyl-alizarine," by Edward 

 SCHUNCK, Ph.D., F.KS. 



In a paper which I had the honour of reading before this 

 Society some time ago* I gave an account of a yellow 

 colouring matter accompanying artificial alizarine, to which 

 I gave the name of anthraflavic acid. Though the sub- 

 stance was at the time new to me and apparently to others 

 also, it is quite possible it may have been previously observed 

 by those working with artificial alizarine, since the crude 

 product is probably hardly ever quite free from it, and its 

 presence would not be likely to escape the notice of any one 

 endeavouring to prepare pure alizarine from the manufactu- 

 red article. 



My analyses of the acid and of its barium and silver •salts 

 led to the formula C16H10O4 for the acid, and I was therefore 

 inclined to view it as a body homologous with alizarine, or 

 alizarine in which H is replaced by CH3. I supposed it to 

 be derived from a hydrocarbon higher in the series than 

 anthracene (C15H12 ?) contained in the ordinary anthra- 

 cene of commerce, a body which is supposed by some che- 

 mists really to exist, and which would stand in the same 

 relation to anthracene as toluol does to benzol. It was 

 necessary to adopt some such hypothesis, since, as Graebe 

 and Liebermann remark, in referring to my experiments, a 

 compound obtained from anthraquinone by the same process 

 as that yielding alizarine cannot possibly contain 15 atoms 

 of carbon. The conversion of the acid into alizarine by 

 the action of fusing caustic potash would however admit of 

 explanation in accordance with my view, since the methyl 



* Proceedings Lit. and Phil, Soc, Session 1870-71. 



