STERILIZATION AND DISINFECTION. 



97 



white as it is consumed. The greatest care must be 

 exercised in cleansing, and especially must care be taken 

 that the porcelain is dry before entering the fire, as it 

 will certainly crack if moist. 



Before using a new filter it should be sterilized by dry 

 heat, then connected with receivers and tubes, also care- 

 fully sterilized. It should not be forgotten that the fil- 

 tered material is still a good culture-medium and must be 

 handled with the greatest care. 



While the filtration of water, peptone solution, and 

 bouillon is comparatively easy, gelatin and blood-serum 

 pass through with great difficulty, and speedily gum the 

 filter, so that it is useless until fired. 



A convenient apparatus used by the author for the rapid 

 filtration of large quantities is shown in the accompany- 

 ing illustration (Fig. 15). 



FIG. 15. Apparatus for the rapid filtration of toxins, etc. 



The Disinfection of Instruments, Ligatures, Sutures, 

 the Hands, etc. There are certain objects used by the 

 surgeon which cannot well be rendered incandescent, 

 exposed to dry heat at 150 C., steamed, or intermittently 

 heated without injury. For these objects disinfection 

 must be practised. Ever since Sir Joseph Lister intro- 

 duced antisepsis, or disinfection, into surgery there has 

 been a struggle for the supremacy of this or that highly- 

 recommended germicidal substance, with two results 

 viz. that a great number of feeble germicides have been 

 discovered, and that belief in the efficacy of all germi- 

 cides has been somewhat shaken; hence the origin of the 



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