DISINFECTION AND DISINFECTANTS. 57 



organic matter, and therefore favor a state of atmospheric purity ; but 

 carbolic acid is not a deodorizer. It makes, but it does not absorb or 

 destroy, fetid vapors : and it is for this reason that M. Lemaire and 

 others have recommended the use of carbolic acid in conjunction with 

 sulphate of zinc, salts of iron, chloride of lime, and so on. 



There is indisputable similarity between the working of putrid 

 germs and of the seeds of the most virulent plagues. Fevers were 

 classed of old as putrid diseases, and any one who has witnessed the 

 prompt decomposition and the foul emanations of fever-stricken beings, 

 whether human or brute, can readily understand that it was no very 

 India-rubber-like stretch of the imagination that led our forefathers to 

 confound contagion with putrescence. 



It is, however, necessary to learn that, in practising Disinfection, 

 we have to neutralize the products of, or check the decay of healthy 

 matter separated from living plants or animals, and that we have like- 

 wise to destroy specific elements of contagion, elements which differ 

 in the various maladies that are known to be transmissible from the 

 sick to the healthy. In order to illustrate this, let us take the case of 

 sewage. The excreta of healthy human beings decompose, and the 

 sewer-gases belong to the class of irrespirable gases which cannot be 

 absorbed into the system without producing serious ill effects, and even 

 symptoms such as characterize a putrid fever vomiting faintness fol- 

 lowed by prolonged stupor fetid diarrhoea, and even death. The re- 

 sults are apparently undistinguishable from typhus fever. The line of 

 demarcation, between a malignant fever produced under such circum- 

 stances and fevers due to a specific virus, has not yet been satisfactorily 

 established. 



The foregoing symptoms result also from decomposing matters pass- 

 ing into the blood otherwise than by the lungs, and whole hecatombs of 

 slain, through the instrumentality of hospital gangrene, pyaemia, puer- 

 peral fever, and allied diseases, testify to the great dangers arising from 

 the diffusion of solid or fluid matters in a state of decomposition. In 

 dealing with the excreta of the sick, it is not the volatile elements and 

 simple gases that we have to fear, but the materials that adhere to any 

 thing and every thing on and around the sick, and, if ever we allow 

 them to pass from the sick-room, it is quite impossible to control them. 

 If we even let them pass in any quantity from room to room or house 

 to house in atmospheric currents, we cannot trace them until they have 

 victimized fresh subjects susceptible to their pernicious influences. 



For our purpose it may be accepted as proved that successful dis- 

 infection must aim at preventing decomposition in simple putrescible 

 matters, or must aim at attacking fever-germs as soon as discharged 

 by the patient. It is desirable that a disinfectant should be an anti 

 septic viz., an agent that arrests chemical change in animal or vege- 

 table matters, and it must be a deodorizer, or capable of fixing the 

 most noxious gases evolved. It has been erroneously believed that 



