600 Sanitary Legislation of the Pentateuch. [October, 
The disposal of blood did not escape the attention of the 
Israelitish law-giver. Directions are given that it is not 
to be let stagnate on the surface of the ground and there 
putrefy, but to be “ covered with dust ” (Leviticus, xvii., 13), 
or, in other words, absorbed in dry earth. Hence it seems 
fair to conclude that more than three thousand years ago 
the peculiarly offensive character of putrescent blood and the 
deodorising and disinfecting property of earth were known. 
Covering with earth is also the treatment specified for ex- 
crementitious matter. To the present day nothing is more 
offensively striking, wherever large numbers of human beings 
are collected away from their settled habitations, than the 
accumulation of filth which defiles the neighbourhood. Not 
merely sieges and other military operations, but engineering 
undertakings, fairs, camp meetings, pilgrimages, are charac- 
terised by nuisances of this nature, which doubtless assist in 
the propagation of typhoid fever, cholera, dysentery, &c., if 
the germs of these diseases are introduced. But Moses 
(Deut., xxiii., 12) gives special direction that excrement shall 
be dug into the earth. IndireCtly this maybe regarded as a 
prohibition against casting filth into the streams and water- 
courses. This view will appear strengthened by the decree 
that the falling of dead animals into small bodies of water 
(Levit. xi., 36) caused them to be regarded as unclean. 
But whilst the use of blood as food is decidedly prohibited, 
and whilst its absorption in earth is enjoined, it figures in 
another capacity which has also a sanitary phase. It has 
been suggested to us that the application of blood to the 
doorways of the houses of the Israelites (Exodus, xii., 22 and 
23) was not merely a symbolical aCt but a prophylactic 
measure. The destruction recorded as coming upon the 
Egyptians was probably some zymotic disease, the proxi- 
mate cause of which would be morbific baCteria in the air. 
It is represented to us as not improbable that these baCteria, 
or other microbia, would be attracted and absorbed by the 
fresh blood sprinkled on the doorposts. This view of the 
case is fortified by the enactment that the Israelites were not 
to leave their houses in the morning. We are very far from 
presenting this supposition as demonstrated. But we under- 
stand that slaughtermen — who are, so to speak, constantly 
surrounded with fresh (in contradistinction to putrid) blood — 
are singularly free from epidemics. We have also witnessed 
experiments, which if not conclusive are at least suggestive. 
Organic solutions and infusions were placed in U-tubes 
through which air was drawn by means of a Sprengel pump. 
Before flowing into one of these tubes the air had to pass 
