90 BULLETIN 414, U. S. DEPARTMENT OF AGRICULTURE. 
again at the rising hour. This latter practice was the most satis- 
factory from every standpoint. Some conditions were found during 
the course of the investigation which could not be justified on any 
possible ground. An indefensible custom which seems almost uni- 
versal at convict camps is to provide insanitary privies for the use 
of the guards and the five or six trusty convicts who work about 
the camp during the day. This practice nullifies the good effects of 
a well-managed pail system, as these insanitary privies are likely to 
make the entire camp insanitary. Such conditions could be cor- 
rected easily by providing covered pails inside the privies. 
PROPER CONDUCT OF PAIL SYSTEM. 
The coal-tar disinfectants of which mention has been made are 
in general use for this purpose and are very satisfactory. The 
United States Public Health Service recommends that 1 quart 
of the solution be used to 6 quarts of sewage. Chloride of lime is 
an excellent and cheap disinfectant and may be used instead of the 
coal-tar product. A solution of the proper strength may be made 
by dissolving 1 pound of the disinfectant in 8 gallons of water and 
should be used in the pails in the proportion of 1 teacupful of the 
solution to each deposit of excreta. The chloride of lime should be 
kept in tight containers as it loses strength rapidly when exposed 
to air. To prevent splashing, a thick piece of paper or several 
small pieces of wood or chips may be dropped into the pail just 
before it is used. The pails should be cleaned and washed daily, 
but under no circumstances should they be rinsed in the vicinity of 
the well or spring. 
At all camps where pails are in use the excreta is disposed of finally 
by dumping into pits and covering with earth. These pits, in all 
cases, were a sufficient distance away from the camps, but it might be 
mentioned that the minimum distance should be 100 yards, and the 
pits should be so placed that they are on a lower level than the water 
supply of the camp. Chloride of lime should be sprinkled into the 
pits at intervals. As the natural agencies of purification are present 
to a greater degree in the upper layers of the soil, it is better that 
excreta should be given shallow burial rather than thrown into deep 
pits. The deeper the pit the greater the danger of polluting under- 
ground water supplies. Instead of the large pits now in use at a 
majority of the camps, shallow furrows or trenches should be dug. 
These should be from 6 to 12 inches deep, and the excreta should be 
scattered along in a layer of about 2 inches in thickness, and should 
be covered immediately with 6 to 12 inches of earth. The furrow 
should be marked with stakes, so that there may be no danger of 
