318 PROCEEDINGS OF SOCIETIES. [^jZhI^.^^^M^^^^^^^ 
know what part electrical and chemical force played in the nervous 
system ? 
Mr. Eoberts said there was one peculiarity of living membranes 
which had not been mentioned. It was this — that wherever there is 
a living membrane the diffusion of salts is stopped ; directly it is dead 
the salts penetrate it. 
Dr. Mmde thought there was a tendency in the present day to 
revive by-gone modes, not only of dress but of thought ; and adduced 
the old scientific sects of the Solidists and Humouralists as represent- 
ing views which have reappeared. The word " vitality " he thought 
could not be dispensed with. We possess very indefinite notions of 
the higher forms of life, and the time has not yet arrived when we 
can say that the phenomena of the higher and lower forms of life are 
one and the same. He wished that Dr. Beale had not confined his 
remarks so exclusively to the lower organisms. 
The Eev. Mr. Mitchell thought a very false analogy had been made 
between crystalline forces and vital forces. He could see no analogy 
in anything belonging to the structural form of crystals to those 
unknown processes which produce a living protoplasm, or those extra- 
ordinary combinations which we call organized bodies. 
The question is, whether we see throughout nature, in the lowest 
forms of organic life, anything analogous to crystalline force. It is 
said that a crystal grows ; but between the growth of a crystal and 
that of the lowest form of organic life there is a striking difference. 
The crystal is homogeneous in its internal structure ; but when we 
take the Foraminifera, we notice the power their protoplasm possesses 
of taking hold of silica and carbonate of lime, and building them up 
into structures as unlike crystals as they can possibly be. The 
tendency of crystals is always to have plane surfaces, the diamond 
being the only apparent exception, but he believed it to be only 
apparent ; whereas in the Foraminifera you find the law of plane 
surfaces set aside, and in their place the most beautiful curvilinear 
forms which can be devised. Again, he could not see, because we can 
make lenses and glasses according to our will, how he was indebted to 
chemical action in the creation of such a structure as the eye. He 
could not help thinking that some higher force than that of mere 
chemical attraction had operated in producing such a structure. 
Dr. Kelly would like to know where the exact line is drawn 
between vital and chemical force. For instance, you may have in 
close proximity an epithelial cell charged with vital force, and near 
the surface one containing dead matter. He wished to know whether 
there was any correlation between the vital and the physical forces, 
and whether matter in certain states is to be called vital, in others 
physical and chemical. 
Dr. Beale, in replying to the various remarks which had been 
made, said that the great point had been hit by Dr. Kelly in his 
inquiry as to whether the living matter shades gradually or abruptly 
into that which is formed. He (Dr. Beale) believed, that while it 
appears to shade gradually, it really passes abruptly. 
