Leaves from the Ship Canal. 219 



years. Not far from this deposit was subsequently found a 

 rude boat (since described before this Society by Mr. 

 Alderman Bailey) about 25 feet underground. This boat 

 lay on a bed of leaves, similar to the one above-mentioned, 

 but much more decayed. 



The dark olive green colour of the leaves first-mentioned, 

 led me to examine them for chlorophyll, by the method em- 

 ployed by Berzelius, Verdeil, Schulze, and Mulder, in which 

 acid is employed in the separation. By thus treating these 

 leaves in comparison with ordinary grass, I obtained by 

 spectroscopic examination absorption bands which were 

 identical. Dr. Edward Schunck, F.R.S., however, who 

 must be regarded as our greatest authority on chlorophyll, 

 subsequently examined the colouring matter of these buried 

 leaves, and in his most interesting paper, given before this 

 Society, he shows that it is not really chlorophyll which 

 exists in these leaves, but modified chlorophyll, which is a 

 very much more permanent colour, produced by the action 

 of acid on chlorophyll. This colour, however, permanent as 

 Dr. Schunck has proved it to be, is entirely destroyed when 

 leaves are exposed to the air and rain and sunshine for a 

 few months, at all events within a year, and it, therefore, 

 seems an interesting fact that this modified chlorophyll 

 should have remained intact, buried in this wet sand for 

 at least some hundreds of years, and probably for one or 

 more thousands of years. I examined the leaves which 

 were supplied to me by Mr. Taylor, which were found under 

 the boat above-mentioned, and I could only detect in them a 

 comparatively very small quantity of the green colouring 

 matter (modified chlorophyll) found in the others. 



