
Oct. 5, 1871 | 
NATURE 
459 

analogies were seemingly strengthened by the increased know- 
ledge which gradually arose concerning the various parasitic 
maladies to which man and the lower animals were liable. 
Writing in 1839, Sir Henry Holland says in his essay ‘fOn the 
Hypothesis of Insect-life as a Cause of Disease,” ‘‘ The question 
is, what weight we may attach to the opinion that certain diseases, 
and especially some of epidemic and contagious kind, are de- 
rived from minute forms of animal life existing in the atmosphere 
under particular circumstances, and capable, by application to 
the lining membranes or other parts, of acting as a virus on the 
human body.” Now, the fact of the multiplication of the virus 
within the body was the peculiarity of these diseases, which, | 
above all others, caused such an hypothesis to be received with 
favour, Causes which are specific, and which seem capable of 
self-multiplication—what can such agents be but living things of 
some kind, plant or animal? This mode of argument was with 
many all-powerful. And when, after the discovery of the yeast- 
plant by Schwann, in 1836, new doctrines concerning fermenta- 
tion began to prevail, the views of those who believed in the 
living nature of the specific causes of epidemic diseases were in 
part strengthened. If all fermentations were initiated by the 
agency of living organisms, and the specific diseases were com- 
parable to processes of fermentation, then how natural was it 
that many who were moreover influenced by the other analogies, 
should be led to imagine that the specific causes of these diseases 
were also living organisms. Only now, attention became di- 
rected to the much lower organisms which are so ‘frequently as- 
sociated with fermentative and putrefactive changes, instead of to 
insects ‘‘ minute beyond the reach of’ all sense.” 
Here, then, is the origin of what in modern times has been 
termed ‘‘ The Germ-Theory of Disease.”? Like homceopathy 
and phrenology, this theory carried with it a kind of simplicity | 
and attractiveness, which insured its acceptability to the minds 
- of many. But, however, it seems to rest upon foundations only 
a little more worthy of consideration than those upon which 
these other theories are based. 
combination with the more generally received doctrines concern- 
ing the origin of life, there has gradually grown up an unwilling- 
ness in the minds of many to believe that these contagious 
diseases can arise de ovo. And this being one of those theories 
which tends to curb inquiry, and to check the possible growth of 
sanitary knowledge in certain highly important directions, it 
seems to me necessary to look with scrutinising care to its foun- 
dations, not only with the view to the advancement of medical 
science, but with the direct object of removing all checks which 
may exist to the growth of sanitary precautions against the origin 
of these most pestilential affections. 
Let us see, then, how far the ‘‘theory” fulfils the conditions 
which all good theories do fulfil—how far it explains a great 
number of the phenomena in question, without being irrecon- 
cilable with others. 
The advocates of the ‘* germ-theory ” have always rested their 
belief in it, in the main, because they considered that it offered a 
ready explanation of the increase of the virus of the contagious 
diseases within the body of the affected person, ‘This increase 
they suppose is not otherwise to be explained. All other con- 
siderations brought forward in support of the theory are just as 
explicable by another supposition. Fully admitting that the 
occurrence of a process of organic self-reproduction would be a 
very adequate way of accounting for the increase of the infecting 
material, we must see whether this mere hypothesis can be re- 
conciled with other characteristics of these affections. In the first 
place, it may be asked, whether such a process is actually known 
to constitute the essence of any general diseases. Because, if so, 
those in which it does occur, ought, in the event of the hypo- 
thesis being true, to present a close similarity to the diseases in 
which such a process is supposed to occur. 
Now, there are certain general diseases which do undoubtedly 
depend upon the presence and multiplication of organisms in the 
blood and throughout the tissues generally. There is the epi- 
demic and highly contagious distemper amongst cattle, known in 
this country by the name of the ‘‘ blood,” and which excites in 
man that most dangerous morbid condition called ‘‘malignant 
pustule.” The researches of M. Davaine* and others have re- 
vealed the fact that this disease is essentially dependent upon the 
presence and multiplication of living organisms, closely allied to 
Vibriones, in the blood of the animals affected, and that similar 
organisms are also locally most abundant in the contagiously in- 
cited .“‘malignant pustule” of man. Unless this latter is 
*® See Comp Rend 1864 and 1865 
Now, owing to its influence, in | 

destroyed in its early stages, the contained organisms spread 
throughout the body and the disease speedily proves fatal. Of 
late, moreover, attention has also been called * to Pasteur’s re- 
searches on the subject of the very fatal epidemic which raged for 
fifteen years amongst the silkworms of France. This affection, 
known by the name of A¢érine, is dependent upon the presence 
and multiplication of peculiar corpuscular organisms, called 
Psorospermia, in all the tissues of the body. Both these general 
parasitic diseases are highly contagious ; both are contagious 
by means of organisms ; and in both the virus does increase 
by self-multiplication within the body of the animal affected. 
What more suggestive evidence could there be as to the truth of 
the ‘‘germ-theory,” say its advocates, than is supplied by the 
phenomena of these two diseases? Undoubtedly the evidence is 
irrefragable as to its applicability to these particular maladies ; 
but then comes the question whether they are comparable with 
the other affections to which the ‘‘ germ-theory ” is sought to be 
applied. And this question must decidedly be answered in the 
negative. These parasitic diseases are sharply distinguished from 
the others by the fact of their almost invariable fatality. Creatures 
or persons once affected in this way are, under ordinary circum- 
stances, thenceforth on the road to more or less immediate death, 
Happily, however, no fatality of this kind is characteristic of 
even such highly contagious diseases as scarlet fever and small« 
pox, or any other of the maladies with which parasitic organisms 
cannot be shown to be associated. Doubtless there are other 
general parasitic diseases amongst animals. In almost all the 
specific diseases to which man is liable, however, I have ins 
variably failed to discover any trace of organisms in the blood. 
The experience of many other observers has been similar to my 
own in this respect. But if living things were really present as 
causes of these maladies, then most assuredly ought they to con- 
form to that fatal type which is almost inseparable from the 
notion ofa general parasitic disease, and which we find exemplified 
by the course of Abrine, the ‘* blood,” and ‘‘ malignant pustule.”+ 
The fact then, that the general tendency in the acute specific 
diseases, is undoubtedly towards recovery rather than towards 
death, speaks strongly against the resemblance supposed to exist 
between them and the parasitic affections alluded to, and also 
against the hypothesis that they are dependent upon the presence 
of self-multiplying germs within the body. Such germs, when 
present, would besure to go on increasing until they brought 
about the death of their host. 
These considerations alone should suffice to inspire grave doubts 
as to the truth of the ‘‘ germ-theory.” And such doubts may be 
reinforced by many others. Thus, the several affections being 
distinct from one another, this theory demands a belief in the 
existence of about twenty different kinds of organisms never 
known in their mature condition, but whose presence as invisible, 
non-developing germs is constantly postulated, solely on the 
ground of the occurrence of certain effects supposed to be other- 
wise incapable of occurring. That, if existent, they are no mere 
ordinary germs of known organisms is obvious, because the 
presence of these has again and again been shown to be incapable 
of producing the diseases in question. Mr, Forster says,£ 
‘There is not perhaps on the face of the earth a human 
creature who lives on coarser fare, or to a civilised psople more 
disgusting, than a Kalmuck Tartar. Raw putrid fish or the flesh 
of carrion—horses, oxen, and camels—-is the ordinary food of the 
Kalmucks, and they are more active and less susceptible to the 
inclemency of the weather than any race of men I have ever 
seen.”§ It has, moreover, been frequently demonstrated, that 
the organisms of ordinary putrefactions may be introduced even 
into the blood of man and animals without the production of any 
of these specific diseases. || Yet is the ‘‘ Antiseptic System” 
* Nature, 1870, No. 36, p. 181. 
+ See paper by Dr. Wm. Budd in British Medical Fournal, 1863. 
t See AMfed.-Chirurg. Rev., 1854, vol. xiii.. where the supposed connection 
of diseases with processes of putrefaction is ably considered by the late Dr. 
W. Alison. 
§ The Bacteria which are sure to be abundant in such food cannot, there- 
fore, be the much talked-of ‘‘disease germs.’ Such a diet is, of course, by 
no means recommended. Epidemic diseases are frequently most fatal when 
they once break out amongst a people whose diet is of this kind (see Dr. 
Carpenter, in Med.-Chirurg. Rev., 1853, vol. xi. p. 173), and could probably 
only be borne in certain climates by persons who lead a very active life. 
See, amongst others, Davaine in Comft. Rend, August 1864, and E, 
Semmer in Virchow’s A7c: s, 1870, Dr. Lionel Beale is well aware of 
this fact, and he, accordingly, whilst adhering to the germ theory, promul 
gates it under anew form. He says (Monthly Micros. Four., Oct. 1870 
p- 205) :—‘‘ Concerning the conditions under which these germs are pro- 
duced, and of the manner in which the rapidly multiplying matter acquires 
sts new and marvellous specific powers, we have much to learn, but with 

