48 THE NATURE OF VIRUS; 
and endosmosis of fluids through membranes; the equili¬ 
brium of these forces being maintained in normal serum, and 
one or the other being rendered preponderant if the specific 
gravity of that fluid is disturbed.— Transactions of the American 
Medical Association. 
THE NATURE OE VIRUS. 
That a considerable number of diseases—embracing 
amongst them some of the most important and some of the 
most frequent occurrence—result from the action of a virus 
or poison, few or none will be disposed to deny ; but if the 
question be asked, what is the nature of a virus, or the 
material that enables the disease to be communicated from 
one animal to another? the answer given by the best in¬ 
structed members of the profession would, we apprehend, 
be far from unanimous. It is well known that in all viru¬ 
lent fluids a clear fluid or serum may be discerned in which 
certain morphological elements, molecules, nuclei, cells, and 
debris of cells, are discernible. The question is, whether 
the poisonous agent is disseminated uniformly through the 
fluid, or is a special quality belonging to or characteristic 
of the corpuscles. This question, interesting' in many 
points of view to the practical surgeon, M. Chauveau has 
undertaken to investigate, and has given the results of his 
inquiries in a series of lectures delivered before the Societe 
des Sciences Medicates de Lyon, and reported in the Revue 
Scientifique. He states in the most unequivocal manner 
that the virulent property is associated, not with the fluid, 
but with the corpuscles held in suspension. This opinion 
he bases on the following facts :—First, that, if virulent 
fluids are diluted with water or other inert material, and 
their activity be then tested by inoculation, it will be found 
that they act, not as if they were uniformly diffused through 
the fluid—that is, not with diminished virulence only, as 
though weakened by dilution,—but irregularly, and as 
though the poisonous quality were limited to particular 
molecules dispersed here and there through the fluid, and 
the more distant from each other in proportion as the fluid 
is more diluted, some of the inoculations failing altogether, 
whilst others are as energetic as usual; and secondly, that, 
if the plasma or serum be carefully separated from the mole¬ 
cules and cells, the former proves inocuous when introduced 
into the system, whilst the latter retain in a high degree the 
