NATURE OF MATERIES MORBI. 
325 
This change takes place with more certainty when the fluid 
acted upon contains among its constituents the substance 
from whose transformation the body suffering decomposition 
was formed.* We have a familiar instance of the action in 
question in the “ turning ” of milk, when placed in dishes 
not scrupulously clean, and to which some particles of older 
milk in a sour state have been allowed to adhere, or when 
intentionally soured, as in the preparing of the yaonrt of the 
Turks and other pastoral people, by the addition of a re¬ 
served leaven of coagulum. Although milk is a homo¬ 
geneous fluid in a state of quiescence, as compared with the 
warm blood of the body, which, to use the beautifully com¬ 
prehensive expression of Liebig, is “ the sum of all the 
organs and tissues in the act of formation/'’ the extreme 
sensitiveness it displays to fermentive influences affords an 
instructive subject for reflection. 
Of the oxidizable impurities which are found in the atmo¬ 
sphere, few are so disposed to combine with active oxygen 
as the decomposing effluvia which proceed from the morbid 
and putrefying bodies, and the effete excretions of men and 
other animals. When in a condition for combination, their 
elements form with that substance compounds of a most 
permanent nature. Assuming those matters to resemble in 
constitution nitrogenized animal bodies, their behaviour in 
the presence of permanganate of potash may be represented 
by the following equation : 
H0 4 C 7 N 2 4- 7(Mn 2 0 7 + ICO) = 
* animal permanganate of 
effluvia. potash. 
HO + 7C0 2 + 2N0 5 + 14Mn0 2 + 7KO 
water. carbonic nitric acid, binoxide of potash, 
acid. manganese. 
Every particle of such substances which thus undergoes 
oxidation represents so much unwholesome matter reduced 
to an inert and innoxious condition, and the quantity of 
permanganate decomposed will correspond exactly to the 
amount of impurities destroyed. Were it possible to bring 
the organic matter, as it exists, for instance, in offensive ex¬ 
halations, into rapid and intimate contact with the perman¬ 
ganate, the process of purification would be instantaneous 
and complete. This, however, is perhaps scarcely attain¬ 
able. The destruction and withdrawal of such impurities as 
obtain contact must, nevertheless, have the effect of lessen- 
* Liebig’s ‘Chemistry of Agriculture,’ by Playfair, 4th ed., p. 382. 
