106 THE MUSEUMS JOURNAL. [VOL. IO. 
Mr. H. Bolton said it seemed to him that the whole question 
was one of bio-chemistry. Possibly we had to consider a chemical 
action upon the stone set up by bacteria somewhat similar in their 
nature to the nitrifying organisms upon which experiments had 
been carried out so successfully at Rothhampstead (Herts). 
The President said he certainly found that a solution of 
copper sulphate preserved the stone better than anything else, 
though the treatment was objected to by some on the ground 
that the stone was coloured by the solution. He hoped that 
members of the Association would seriously consider the matter 
and carefully weigh the points raised by Dr. Bather. He thought 
that the germ theory advocated in the paper was acceptable on 
the ground that it was possible for a bacillus to exist in stone. 
The erosion had been most marked during the past twenty years, 
and this was a fact worth noting, suggesting as it did that the 
organism concerned had been at work during a definite period. 
