EASTERN COUNTIES VETERINARY MEDICAL ASSOCIATION. 381 
dent upon them from our world. It will be perceived that issues 
of immense importance are involved in this question. Dr. 
Burdon Sanderson says that in all acute infective inflammation 
we have microzymes (a species of Bacteria) abounding in the ex¬ 
udation liquids and also in the blood whenever these poisonous 
germs enter the system, whether by means of respiration, by the 
food, or by the skin, if they find a suitable media they germinate 
and at once multiply indefinitely, creating in the system an 
amount of molecular disturbance, or ferment in exact ratio to 
the state of predisposition or degree of susceptibility of the 
animal. If the quantity be small and the constitution strong 
and healthy, it may prove innocuous ; but not so if the vitality of 
the subject has been reduced to a low point, having been living 
in impure air and upon unwholesome food, then it will take on a 
virulent form, and will prove to our cost the danger of defying 
laws which experience and science has proved necessary to avoid 
contagious zymotic or preventable diseases. This brings me to 
the next question. 
Contagium .—This is considered not merely an influence, it is 
something substantial. It resembles solid, round, or ovoidal 
corpuscles, often quite structureless ; it would appear to be some¬ 
thing that is alive. The power it acquires in originating a 
diseased process is one which it acquires by virtue of its having 
been a constituent of diseased living protoplasm. It may spring 
from diseased tissue itself, or it may be dependent for existence 
on the tissue of independent organisms. Dr. W. Roberts gives 
the name of pathophytes to the organisms supposed to produce 
the phenomenon of infective diseases, and we know that this con¬ 
tagium can retain its virulent and infectious qualities for long 
periods of time. It possesses a long enduring dormant vitality ; 
it can get firmly fixed in and accumulate on the walls, timbers, 
and floors of stables and other places, and whenever favorable 
conditions supervene its energy is liberated by the proper 
stimuli. It will then crowd the air and prove itself as intensely 
venomous as at first. Professor Tyndal informs us that putre¬ 
factive organisms fail to produce any deleterious effects upon 
animal life in its healthy state; that the gases given off during 
putrefaction are not of themselves infectious. 
Professor Tyndal, in “A Battle with an Infective Atmosphere,” 
shows us that the element of contagium is an essential part 
necessary to produce any contagious disease. Let us for a 
moment contemplate a case in point. We see a virulent epidemic 
commence and rage in a certain district. The more intelligent 
persons of the place at once set about to ascertain the cause of 
it. In the majority of cases it is soon found out, and measures 
are immediately taken to remove it. In the meantime numbers 
of men and women have died, and large numbers of others have 
imbibed more or less of the poison germs, which have been gene¬ 
rated in a given spot—atmospheric action on decomposing 
matter. Now, does the epidemic cease the moment the original 
