i88i.] 
Analyses of Books. 
615 
Proceedings of the Literary and Philosophical Society of Liver- 
pool during the Sixty-eighth Session , 1878-79. No. XXXIII. 
London : Longmans and Co. Liverpool : D. Marples and 
Co. (Limited). 
This volume contains some very valuable matter. Dr. J. J. 
Drysdale contributes a very elaborate memoir on the “ Germ 
Theories of Infectious Diseases.” He warns us that we have 
no warrant for supposing that the days of epidemics are over. 
“ The immunity of any generation from the greater plagues 
may be merely an interruption of the course liable to terminate 
any year by a fresh outbreak of some old or a quite new plague.” 
Following Liebermeister, he divides the diseases in question 
into three classes : — the truly contagious, where the materies 
morbi is reproduced in the organism suffering from disease, such 
as small-pox, plague, typhus, &c. ; the miasmatic, such as the 
remittent and intermittent marsh-fevers, where the poison is 
developed externally to the body ; and lastly, the miasmatic 
contagious diseases, such as cholera, dysentery, and typhoid, 
where the secretions of the infeCted persons undergo a further 
development out of the body. On the exaCt nature of infectious 
matter it may be at any rate regarded as ascertained that the 
specific power does not reside in anything gaseous, liquid, 
soluble, or diffusible, but in particulate matter. Such matter 
will either be an organised ferment, a parasite, or a portion of 
living matter capable of transplantation and growth in the bodies 
of other persons. The inference, however, that the growth and 
development of parasitic microphytes in the blood is the cause 
of specific diseases in general, Dr. Drysdale considers as some- 
what hasty. He maintains that “ one of the chief aims of 
medicine should now be to turn these fearful engines of power 
(infectious diseases) into agents of protection against and cure of 
the very evils produced by their uncontrolled natural operation.” 
The memoir is deserving of very careful perusal, and of a much 
more thorough investigation than space allows us to give. 
The Rev. H. H. Higgins undertakes to give an answer in the 
negative to the question ‘‘Is Nature cruel?” By cruelty he 
understands that which is exhibited in the infliction of needless 
and profitless pain.” In examining the argument it may be 
sufficient to turn to the learned author’s defence of the mosquito 
as a sanitary agent. Admitting for argument’s sake, — and it is 
an enormous admission, — that the tundras of Siberia and the 
plains of the far north-west of America would suffer from 
malarial fever were it not for the operations of the larvae of 
mosquitoes, overlooking the fad — referred to by Dr. Drysdale in 
the memoir just referred to- — that these inseCts are the conveyers 
of disease from person to person, we point to the circumstance 
hat millions upon millions of them live and die without ever 
