264 
Proceedings of the Royal Society of Edinburgh. [Sess. 
Many others might be added. For instance, tartaric acid : — 
C 
"0 " OH "I 
.... 0 o 
c 
H 
O OH 
> 
C 
0 -OH 
" "H* 
And the bibasic acid 
produced from it by 
the action of heat 
will be perhaps 
C'O- OH 
: O 2 
c; 
c: 
• H 
:::o 2 
• H 
tartrelic 
acid. 
C 
••• o 2 
-o - Oil 
OH 
It is my intention to consider, in a future communication, the second type, and 
to apply my views to the cyanogen combinates, etc. 
* A horizontal dotted line is erroneously printed here in the original. 
