58 ANTISEPTIC TREATMENT OF WOUNDS. 
case, in directly connecting the skin and the superficial layers 
of the tissue by suturing, cavities are left at the bottom, which 
easily lead to an accumulation of exudations, and which are 
thus direct breeding cavities for infectious germs. To pre- 
vent such conditions and yet at the same time to bring the 
greater part of a wound to a close prima intentione, such 
cavities have to be kept accessible for disinfection. Drainage 
serves this purpose, that is, the exudations are drained from the 
tissue cavities by means of tubes, which are manufactured 
trom different materials. 
LISTER used rubber hose as drain tubes, which were of 
different diameters and had side openings for the escape of the 
exudations. These drainage tubes are first disinfected by put- 
ting them in a 5 per cent. carbolic or sublimate solution, and 
are then used. 
SCHEDE used instead of rubber tubing pigtails made oi 
twisted glass threads ; also skeins of horsehair or catgut threads 
were recommended, but, although capillary attraction acts 
favorably in this mode of drawing off the exudations, a gener- 
alization of this method has not been accomplished. Likewise 
the use of absorbable drainage tubes. such as NEUBER made 
out of decalcinated bird bones did not become popular, al- 
though these drains, on account of their being absorbed, do 
not possess the disadvantages of the rubber drains. Though 
the drainage doubtlessly offers many advantages to the healing 
of the wound, certain disadvantages are attached to it so that 
partly by changing the material and partly by taking special 
technical measures, we try to avoid these disadvantages. Since 
we are never entirely successful, it is necessary, to limit them 
by following certain rules when adjusting a wound drainage 
so as to avoid as much as possible any hindrances to the heal- 
ing of the wound. First of all, the drainage tube being always 
a foreign body, prevents a direct union of the respective parts 
on account of its lying between the surfaces of the wound. 
Therefore, it is compulsory, if the wound heals regularly oth- 
erwise, to change the bandage after a time in order to remove 
this drainage tube. 
