208 THE HOUSE FLY—DISEASE CARRIER 
water with a film of kerosene on top in an ordinary 
unprotected tub. pail, or barrel system is that if the 
water is too deep splashing occurs, and a wet system 
calls for a large receptacle. 
In a recent publication, Stiles (1910) covers the whole 
subject, and gives directions for building a really sani¬ 
tary privy, indicating that any fourteen-year-old school¬ 
boy of average intelligence in mechanical engineering 
could, by following the plans given, build a sanitary 
privy for his home at an expense for building materials, 
exclusive of receptacle, of from five to ten dollars, ac¬ 
cording to locality. The plan (directions for its con¬ 
struction are printed as Appendix IV) provides for a 
flv-proof structure, well ventilated, with a receptacle 
for the excreta mounted on a floor and protected from 
behind by a hinged door through which it can be re¬ 
moved. The receptacle always contains the necessary 
amount of water with a film of kerosene floating on it. 
The most casual observation will indicate when to re¬ 
new the water and kerosene and when to empty the 
receptacle. 
Since the publication of the bulletin in question, 
Lumsden, Roberts, and Stiles, of the Public Health 
Service, have devised an additional arrangement which 
they have had in constant use in the Hygienic Labora¬ 
tory at Washington for several months. Concerning 
the practical workings of this apparatus they seem 
very enthusiastic. The writer himself has visited it 
and found it perfectly unobjectionable after being in 
use for more than three months without having been 
