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brought me the specimens, which he had met with during the 
demolition of some old buildings. The drawings are of the 
natural size. It is very rarely that such perfect specimens are 
found, showing, as this one does, the curious structure of the 
species, and its connexion with both the pore and the gill-bearing 
divisions of fungi.” 
Mr. Dancer exhibited some sand from the sea-shore at Santos, 
South America. This sand was remarkably silvery in appearance, 
a large portion of it consisting of minute plates of mica, and very 
transparent fragments of quartz, which made it an interesting 
object for the polariscope. It was rich also in Foraminifera, 
spines of Spatangus, and fragments of Coralline. 
“ Remarks on Molecular Activity as shown under the Micro- 
scope,” by J. B. Dancer, F.R.A.S. 
The author stated that, during the last thirty years, he had met 
with many microscopical observers who were not acquainted with 
the phenomenon to which the name of molecular action has been 
given. This class of microscopists had confined their attention 
to objects requiring a very moderate amount of magnifying power, 
and generally to dry objects ; but when their investigations 
extended to minute objects immersed in fluid which required 
powers of 800 to 1500 diameters, they were startled by the appear- 
ance of particles in active motion, not moving in a direct line, but 
ribrating as if attracted and then repelled by each other, some 
single, and others in clusters. 
Many instances have come under the author’s notice in which 
these objects have been regarded by microscopists as animalcuhe. 
They have given rise to many very ingenious speculations, some 
of which are connected with spontaneous generation; these 
observers would have been saved much labour if they had been 
acquainted with the experiments of the late Dr. Robert Brown on 
active molecules. 
The author does not imagine that the members of this section 
are wholly unacquainted with the experiments of the early micro- 
scopists on this subject, but in the abscence of more important 
matter he thinks a brief account of the early observations on 
these so-called active molecules may interest them. 
The moving particles had been noticed by Leuwenhock, 
Stephen Gray, Button, and others who supposed them to be 
animated matter. 
In the year 1827 the late Dr. Robert Brown, whilst engaged 
in the microscopical investigation of the unimpregnated ovulum, 
noticed that the pollen of the Clarckia pulchella was filled with 
particles which appeared in active motion when immersed in 
water. These observations were followed by the examination of 
the pollen of other plants, the particles of which he found to 
exhibit similar activity. For some time he was exceedingly per- 
plexed with these phenomena, and was disposed to believe that he 
had really seen in these minute bodies the supposed constituents 
or elementary molecules of organic bodies, first so considered by 
