ON THE REAL NATURE OF DISEASE GERMS. 859 
Living Germs of Fever . — As was shown experimentally by 
Dr. Sanderson, a mere trace of blood serum was sufficient to 
propagate cattle plague. A very small portion of blood or 
of the tissues of an infected animal had the same effect. 
Nay, the contagion is so subtle that in this as well as in 
many other contagious diseases, the breath of the diseased 
organism contains numbers of the potent particles of poison, 
and in this manner the very air of a considerable space or 
even district may become infected. 
In the blood in the smaller vessels, as well as in the mucous 
secretions of the mouth, intestinal canal, and in the milk of 
animals suffering from this disorder, I have found multitudes 
of minute particles of bioplasm, which, as long as they re- 
main alive, are, without doubt, disease-carrying particles. 
The disease germs of many contagious fevers will retain 
their vitality in water and other fluids for a length of time, 
and there is reason for concluding that some of these poisons 
not only grow and multiply in media different from any in 
the organism, but that in the course of such growth and 
multiplication they acquire still more virulent properties. 
Dr. C. Macnamara has discovered that cholera poison in 
water after exposure to the sun for a few hours becomes ex- 
tremely virulent, and that this period corresponds with the 
development of multitudes of vibrios ; but that after the 
lapse of a day or two, when the vibrios will have disappeared 
and given place to ciliated animalcules, the fluid may be 
taken with impunity. 
Syphilitic Disease Germs . — This is another of those remark- 
ably special living poisons which may be suspended in serum 
and other fluids, and retain its vitality for a length of time. 
There is reason for thinking that a single epithelial cell 
may carry multitudes of active particles of syphilitic poison, 
one of which introduced into the blood or lymph of a healthy 
person would probably grow and multiply, and give rise to 
pathological changes characteristic of, and quite peculiar to 
this particular poison. 
We know that the syphilitic poison may retain its specific 
characters in the organism for years, from time to time giving 
rise to local pathological phenomena, which are characteristic 
of this kind of morbid bioplasm. It is impossible from the 
facts of the case to arrive at any other conclusion than this : 
that a certain portion of the living matter remains in the 
organism, and that under certain favorable circumstances 
this grows and multiplies, producing disease. Particles of 
this virulent poison may be transferred from the infected 
organism to a healthy one, and contaminate it, even many 
