124 THE MICROSCOPE. Aug, 



blowfly and examine carefully at the base of the spiral 

 tubes, and between them will be found the teeth; focus 

 on the front one, then on the middle one, and lastly on 

 the back or lower one. This will give a good idea of the 

 seA'eral rows, as well as the individual teeth. In conclu- 

 sion I will now say, in answer to the query : Do flies 

 have teeth ? — "Yes, I think they have." 



Disinfecting with Sulphate of Copper. 



By M. H. VINCENT, 



ALGIERS. 



The best agent for disinfection of excrements and of 

 the contents of cesspools is sulphate of copper, especially 

 if care has been taken to reinforce its activity by means 

 of a quantity of sulphuric acid equal to 10 per cent of 

 the excrements. Under these conditions the following 

 results are obtained : 



1. For normal stools, putrefied or not, mixed with urine 

 and at an average temperature of 16°C., disinfection is ob- 

 tained in twenty-four hours, if a proportion of sulphate 

 of copper equal to 6 grams for 1000 c.c, or 6 kilo- 

 grams per cubic meter is used. 



2. For disinfection of typhoid stools and the destruc- 

 tion of Elberth bacillus, the proportion of sulphate of 

 copper is no more, in the same conditions of tempera- 

 ture, than 5 grams for 1000 c.c, or 5 kilograms by 

 cubic meter of excrements. 



3. Three grams, 50 centigrams, only of the same disin- 

 fectant are sufficient to neutralize 1000 c.c. of matters 

 containing cholera bacillus. 



In the two last cases, disinfection is obtained after a 

 twelve hours' contact of the matter with the antiseptic. 

 — Translated by Rene Samson. 



Catalogues of W. & H. Seibert are supplied by Fr. J. Em- 

 merich, Sr., No. 74 Murray St., New York, N. Y. O. E, S. 



