72 SCIWEINICIE, 
creases. Some parts resist more than others; the osseous 
parts more than the membranous. 
The heart of the germ, then, needs a force propor tioned 
to overcome this resistance. Its force is in its or ritability, 
or in the power to contract when brought into contact 
with a liquid. Augment this irritability, and you augment 
its impulsive force. 
Fecundation increases, without doubt, this force, and 
it alone can do that: since it is only by its intervention 
that the germ succeeds-~in freeing itself from the narrow 
ee which restrained it in its first stage. 
t “he fecundating liquor is, then, a true stimulant, which, 
ee to the heart of the germ, excites it powerfully and 
communicates to it a new activity. This is what we call 
conception. Movement once impressed on this little prime 
mover is conserved by the unique energy of its admirable 
mechanism. 
But it does not sufhce that the heart acquire a force 
capable of overcoming the resistance of solids: the fiuid 
which it sends them for nourishment must be proportioned 
to the- marvelous fineness of the vessels. A blood such 
as ours would not circulate. The blood of the embryo at 
first is a whitish liquid; it turns yellow by degrees and 
finally becomes red. ‘he impulse of the heart dilates 
the vessels more, and they admit larger particles, hetero- 
geneous and colored. 
The generative liquor is mot, therefore, a simple 
stimulant: it is teides a nourishing fluid, appropriate to 
the extreme delicacy of the parts of the germ. It ful- 
filled already in the body of the fertilizing individual the 
functions of a nutritive fluid: it made the comb and spars 
grow and gave strength to ali parts. You recall the 
degeneracy of the capon, and how it differs from the cock. 
You might have many more proofs that the generating 
fluid is the first aliment of the germ. 
Transported by the arteries to all the parts, it unites 
with them in a fixed manner, according to. the proper 
nature of each. The chick is not slow to lose its form of 
tadpole. Wings, legs and feet proceed out of the long 
tail; everything comes out, fashions itself and arranges 
itself on anew model. ‘The little animal, stretched out at 
first in an almost straight line, curves itself more and 
more. It invests itself more and more with muscles, 
tendons, bones and feathers, and in 18 or 20 days it is a 
perfect chick. B. 
VACCINATION: 
BY J. N. HALL, M.D., DENVER, COLO. 
In view of the periodical crusades againt compulsory 
vaccination by certain enthusiasts opposed to the practice 
I have thought that it might be of interest to the readers 
of Sctence to look at a few of the results to be deduced 
from recent statistics upon the subject. The reason why 
no thoroughly scientific study of the anti-vaccination side 
of the matter has been made would seem to lie in the 
fact that no scientific mind could view the situation in a 
judicial way without seing that all of the facts are upon 
one side, and that the one of the advocates of vaccination. 
With this prelude I will allow the facts to speak for them- 
selves. = 
In 1874 the compulsory re-vaccination 
operative in Prussia. (See Dr. Sykes’s ** Public Health 
Problems,’ London). By its provisions, every infant 
must be re-vaccinated, and every scholar in public and 
private schools must be re-vaccinated at the age of 
twelve years. If we take the average number of deaths 
from small pox per 100,000 living in Prussia, we find 
that for the five years preceding the introduction of com- 
pulsory vaccination the number was 113+, Since the 
law became 
Vol. XXIII. No. 575 
law went into effect, in but one year, up to 1883, has it 
reached 4 per 100,000. The average is much less. I have 
not at hand the figures since that time, for the whole 
population, but in the Prussian army, where all the con- 
ditions are under better control, the ‘results are so much 
better that I will quote them. ‘This is easily done, for 
with the exception of a single death in 1885, the name 
small pox has not appeared asa cause of death in the 
annual reports since the law went into effect. It should 
be borne in mind in this connection that Prussia is con- 
stantly exposed upon its Russian and Austrian borders to 
the disease. 
As tothe death rate in vaccinated and unvaccinated 
persons, we may quote the conclusions of Dr. Barry, in 
his report of the epidemic of 1887-8, in Sheffield, England. 
Without quoting the figures, it will suffice to present the 
statement that ‘‘the children vaccinated, had, as com- 
pared with the unvaccinated, a 20-fold immunity from 
attack, and a 48o0-fold security against death from small 
pox; the persons over ten years of age, once vaccinated, 
had a 5-fold immunity against attack, and a 51-fold 
security against death; and the twice vaccinated, a 3r-fold 
immunity ‘from attack, and a 640-fold security against 
death.’ 
Inasmuch as the objections to vaccination ‘on the 
ground that syphilis and lepresy may be transmitted may 
be completely done away with by the use of heifer-virus, 
we need not discuss the matter. There is, indeed, a 
certain element of danger in vaccination, as in every other 
thing of established value, but it is strange that im the 
face of such evidence as may be obtained from scores of 
reports of boards of health, medical departments of 
armies, etc., etc., there are still found those who deny 
the value of the most beneficent discovery ever made by 
man. here is good reason for hoping that we may soon 
be able to control in similar manner many other of the 
contagious diseases which have in the past made such 
havoc with our race. 
—‘‘ The Political Economy of Natural Law,” by Henry 
Vood, which appears from the press of Lee & Shepard, 
of Boston, is virtually an enlargement of a work pub- 
lished seven years ago under the title, ‘‘ Natural Law in 
the Business World.” The author’s main thesis, that all 
industrial operations are governed by natural law, is of 
course nothing new, nor is his presentation of it more 
scientific than that of the regular economists, but less so; 
yet there is much in his book that may be useful if it 
reaches the right class of readers. Those who wish a 
thorough and scientific formulation of the known laws of 
economic life will prefer the regular treatises; but those 
who do not relish the hard study that such treatises 
require, end who like a more popular mode of treatment, 
will find in this work some useful lessons on the matters 
with which it deals. ‘That the law of supply and demand 
cannot be set aside by artificial restraints, that combina- 
trons of laborers are often tyrannous, and combinations of 
capital tend to overreach themselves, and that socialism, 
if once established, would carry within itself the seeds of 
its own dissolution, though familiar truths to well-informed 
men, are not so widely known in the business world as 
they ought to be; and Mr. Wood’s statement of them may 
attract readers who would never read the elaborate works 
of Mill and his successors. Mr. Wood takes extreme 
eround against legislation on business matters, but makes 
an exception in favor of the protective tariff, which seems 
to be a pet measure of his. On the whole, however, he 
is open-minded and fair, and his opinions in the main 
are such-as the best economists will approve, 
