ELEVENTH ANNUAL MEETING. 71 
oyster very deeply tinged with green in various regions, e€s- 
pecially in the liver, connective tissue and mantle. The frag- 
ments were burned in a bead of microcosmic salt and chloride of 
sodium on aclean platinum wire ina gas flame; this test did 
not give the characteristic sky-blue flame which should have 
been developed had there been the minutest trace of copper pre- 
sent. Dr. Taylor, chemist of the U. 8. National Museum, has 
also recently called my attention to the fact that Dr. F. M. End- 
lich has made an exhaustive chemical investigation of the green 
substance found at times in oysters, and arrived at the conclu- 
sion that the coloring matter, whatever it may be, is entirely 
inert and harmless. Dr. Endlich’s researches are noticed in the 
annual report of the Smithsonian Institution for 1879. 
It is therefore clear that the substance, whatever it may be, is 
not a corrosive metallic poison derived from copper, which if 
present would almost undoubtedly be detected by a peculiar 
acrid metallic taste, which would be experienced when one ate 
such oysters. In making some practical tests as to the relative 
qualities of such oysters as compared with white-fleshed ones, 
opportunities for which were kindly furnished me by Mr. J. M. 
Carley, of Fulton Market, I failed to detect the slightest differ- 
ence of flavor. Such also is Professor Leidy’s verdict, who in- 
forms me that he made a similar experiment, and a restaurateur 
with whom I discussed the matter, declared that he was in the 
habit of selecting them for his own eating, preferring their fla- 
vor to that of the white oysters. 
It has been objected that the green color could not be derived 
from diatoms, because these organisms are as a rule, apparently 
brown rather than green. This objection I find to be based up- 
on a misapprehension of the structure of the Dzatomacew, as may 
be gathered from the following general statement taken from 
Sachs’ “ Text Book of Botany,” one of the latest and highest 
authorities. On page 222 he says: “ The diatoms are the only 
alge except the Conjugate in which the chlorophyll occurs in the 
form of discs and bands, but in some forms it is also found in 
grains, and the green coloring matter is concealed like the chlor- 
ophyll grains in Fucacez, by a buff-colored substance diatomine 
or phycoxanthine.” It appears, then, according to the foregoing 
