HEAT. 65 



the albumin and its disinfecting properties may be 

 entirely destroyed ; we may in a very short time have 

 little else than water containing a precipitate of albumin 

 and mercury, in so far as its value as a disinfectant is 

 concerned. 



Though the other inorganic salts have not been so 

 thoroughly studied in this connection, it is nevertheless 

 probable that the same precautions should be taken in 

 their employment as we now know to be necessary in 

 the use of the salts of mercury. 



Where it is desirable to use chemical disinfectants in 

 the laboratory, much more satisfactory results can 

 usually be obtained through the employment of carbolic 

 acid in solution. A 3 or 4 per cent, solution of com- 

 mercial carbolic acid in water requires a somewhat longer 

 time for disinfection of such resistant objects as the spores 

 of the bacillus anthracis, but it is at the same time open 

 to fewer objections than are solutions of the inorganic 

 salts. For less resistant organisms its action is usually 

 complete in from twenty minutes to one-half hour. 



In the laboratory heat is the surest agent to employ. 

 All tissues containing infectious organisms should be 

 burned, and all cloths, test-tubes, flasks, and dishes 

 should be boiled in 2 per cent, soda solution for fifteen 

 to twenty minutes, or placed in the steam sterilizer for 

 half an hour. 



Intestinal evacuations may best be disinfected with 

 milk of lime, a mixture composed of lime in solution and 

 in suspension, ordinary fluid " white-wash." This 

 should be thoroughly mixed with the evacuations until 

 the mass reacts distinctly alkaline, and should remain 

 in contact with the infective substance for one or two 

 hours. 



