MARCH 21, 1884.] 
Besides a dozen or so of pages devoted to 
the rdle of the ‘ Bacteria in surgical lesions,’ 
and having chiefly a medical interest, the rest 
of the book is devoted to a long and careful 
treatment of the ‘ Bacteria in infectious dis- 
eases,’ and to the literature of bacteriology. 
These and the part on ‘ Technology’ include the 
cream of the work. 
At the start the author incidentally draws 
a subtle distinction, which may or may not be 
generally acceptable (p. 236), — 
“The practical results of etiological studies, so far 
as the prevention and cure of disease are concerned, 
are likely to be much greater than those which have 
been gained by the pathologists; ’’? — 
adding directly in a tone of liberal conserva- 
tism, which no one can help admiring, especially 
as it comes from one who is in the advancing 
column, — 
‘‘and if the time ever comes, as now seems not 
improbable, when we can say with confidence, infec- 
tious diseases are parasitic diseases, medicine will 
have established itself upon a scientific foundation. 
But this generalization, which some physicians think 
is justified even now by the experimental evidence 
which has been so rapidly accumulating during the 
past decade, would, in the opinion of the writer, be 
premature in the present state of science. And for 
the present it seems wiser to encourage additional 
researches, rather than to attempt to generalize from 
the data at hand. . . . Those who have had the most 
experience in this difficult field of investigation are 
commonly the most critical and exacting with refer- 
ence to the alleged discoveries of others.”’ 
Dr. Sternberg sees clearly enough that one 
of the most interesting theoretical questions in 
this whole subject which remains still unsolved 
is, how does inoculation or vaccination protect ? 
or, in his own words, what is ‘‘ the rationale 
of the immunity produced by protective inocu- 
lations? . . . Recovery, after inoculation with 
attenuated virus, is more easy to understand 
than is the subsequent protection”’ (p. 241). 
Lecturers upon the subject often pass lightly 
over this point, and, by a comparison with a 
fermentation in a barrel of cider for example, 
say, ‘‘ And just as a barrel of apple-juice can 
ferment but once under the same germ, so a 
man usually has the small-pox but once ;’’ the 
idea being implied, that, as the alcoholic fer- 
ment has eaten up its food in the barrel, so the 
hypothetical small-pox plant has taken out all 
the available food-material from man, its living 
prey. Pasteur maintains a position like this ; 
while Sternberg denies that it is a satisfactory 
explanation, and brings forward a lengthy argu- 
ment in opposition, some of the points of which 
do not seem to us well taken. It is, however, 
the sufficient and fatal objection to the line of 
thought outlined above, that, while the barrel 
SCIENCE. 
363 
of apple-juice is a not-living medium, the liv- 
ing organism is undergoing constant repair, is 
even growing (in the technical sense) till death 
comes, and is therefore no fixed quantity, either 
in composition or condition. Dr. Sternberg 
would solve the problem by considering the 
acquired protection to be a ‘ tolerance,’ a ‘ re- 
sistance’ of the protoplasm to the new condi- 
tion; e.g. (pp. 248-249), ‘* during a non-fatal 
attack of one of the specific diseases, the 
cellular elements implicated, which do not 
succumb to the destructive influence of the 
poison, acquire a tolerance to this poison.’’ 
This would explain a temporary immunity, 
—would prevent a patient from ‘giving’ the 
disease to himself over and over again, — but 
would not explain a lifelong immunity, since 
new, and perhaps non-tolerating, non-resisting 
cells are being constantly produced from the 
old ones. The cells which actually suffered are 
therefore supposed by Dr. Sternberg to ‘‘ac- 
quire a tolerance to this poison, which is trans- 
missible to their progeny and which is the 
reason of the exemption of the individual from 
future attacks of the same disease.”’ 
This hypothesis is certainly clear, and it is 
only befogged by the author’s illustration (7?) 
drawn from budding and grafting. 
In view of the fact that bacteria are now 
believed to do their work largely by producing 
a genuine not-living poison which affects the 
living cells, the following is of interest : — 
‘* The tolerance to narcotics — opium and tobacco 
—and to corrosive poisons — arsenic, which results 
from a gradual increase of dose, may be cited as an 
example of acquired tolerance by living protoplasm 
to poisons which at the outset would have been fatal 
in much smaller doses. 
‘The immunity which an individual enjoys from 
any particular disease must be looked upon as a power 
of resistance possessed by the cellular elements of 
those tissues of his body which would yield to the 
influence of the poison in the case of an unprotected 
person.”’ 
The reader must recollect, however, Hux- 
ley’s discussion of ‘ aquosity ’ and ‘ horologi- 
ty,’ and remember that in such sentences as 
the following we are doing little more than for- 
mulating our ignorance : — 
‘* The resistance of living matter . . . isaproperty 
depending upon vitality.’’ 
The question is often raised, Where do the 
pathogenic bacteria come from? Dr. Stern- 
berg says in this connection, — 
‘‘TIf we suppose that under certain circumstances 
the conditions relating to environment approach 
those which would be found within the body of a 
living animal, we can easily understand how a micro- 
organism which has adapted itself to these conditions 
