20 BACTERIOLOGY 



at all events, may be sterilised over a gas or spirit flanie 

 after being cleansed with alcohol and corrosive sublimate, 

 after which they are laid, with the heated side uppermost, 

 on a sheet of clean paper and merely protected with a glass 

 cover which has been likewise cleaned by means of alcohol 

 and corrosive sublimate, or even with a cleaned soup-plate. 

 Cleanliness of all objects coming in contact with the 

 bacteria is of particular importance ; and therefore it fol- 

 lows that in the practical application of bacteriology to 

 surgery there is need of the utmost care in the cleansing 

 of hands, instruments, and dressings, in order to render 

 an aseptic procedure possible. For this purpose a thorough 

 brushing of the hands (which have first been carefully 

 cleansed with soap), followed by rinsing with alcohol and 

 ether and washing in a -f-^th. per cent, solution of corrosive 

 sublimate, is absolutely necessary. 



Apparatus and Eeagbnts 



A microscope provided with Abbe's illuminating appa- 

 ratus, ordinary objectives of various powers, and an oil- 

 immersion lens. 



The steam steriliser described above, with the corre- 

 sponding gas-burner and a thermometer. 



Incubator. — The warm chamber or incubator consists of 



a quadrangular chest of stout sheet metal with double 



walls, the space between which is filled with water and has 



two apertures, one for a thermometer dipping into the 



water, while into the other a ther mo-regulator is inserted. 



The chest is closed above by a suitable lid, and the whole 



apparatus is covered with felt, with the exception only of 



the lower surface, to which heat is applied. The interior 



space may be subdivided by partitions.' A glass gauge, 



' [The incubator chiefly used in this country diiJers slightly from that 

 described in the text, as it opens at the side instead of above, and is closed 



