INFECTION OF WOUNDS. 17 
HESSE, also, with his well-known apparatus, collected and 
cultivated the germs contained in the air, and at the same time 
discovered some of the already known pathogenic fungi. As 
far as the quantity of these organisms referred to in the air is 
concerned, it has been proven that in quiet air, according to 
the laws of nature, the fungi fall to the bottom. But since 
we have quiet air in neither our dwellings, stables, nor the out- 
side, the quantity of fungi will vary according to the amount of © 
movement in the air. This is not an absolute rule, as the 
amount of moisture in the air as well as its density cuts a 
figure, but at any rate a strong draft brings us more germs in 
the same length of time than quiet air would. 
As far as the air, especially in the rooms where our patients 
are, is concerned, besides the factors named above, several oth- 
er factors which are responsible for the condition of the air, 
must be considered, namely, rough provender (grass, hay, 
straw), bedding and the animal excrements. It may be re- 
marked here that the above named substances, if they are in a 
dry condition, easily part with some of their germs as they 
whirl in the air when being thrown around, but in a moist con- 
dition they do not affect the air as far as its containing fungi 
is concerned. The experiments of CADEAC and MALET with 
the emanations of rotting organic substances make this latter 
supposition probable. As far as the special relation of the feed, 
resting place, and excrements, to wound infection is concerned, 
we will go deeper later. Another question which was referred 
to during occasional discussions of infection of wounds is, 
whether the expired air of the operator contains pathogenic 
germs? In this case, also, the experiments of CADEAC and 
MALET are decisive, as they could not detect any specific 
micro organisms in the expired air of horses which were af- 
fected with specific maladies of the respiratory organs. 
2. HANDS AND CLOTHING OF THE OPERATOR. 
As the surgeon continually operates with his hands in the 
immediate vicinity of the wound, special attention must be 
given to them as carriers of infection. The hands have the 
