H. Orr 
277 
Test E. “Small size’’ Canadian Disinfestor at Dressing Station of 74th 
Field Ambulance, Grand Servins. 
The charge consisted of blankets and shirts. 
The thermo-couple was placed in the folds of a blanket as in Test C. 
In 4 minutes the temperature had reached 55*5° C. 
In 10 
In 15 
In 20 
In 25 
In 30 
All lice were killed and eggs shrivelled. 
9 9 
9 9 
9 9 
99 
99 
9 9 
9 9 
9 9 
9 9 
9 9 
61-0 
66-0 
71*0 
73-0 
78-0 
The foregoing are typical results of measurements taken under various 
conditions. They show that during the normal working of “the Canadian 
Disinfestor,” the temperature reached in the clothing is higher than that 
necessary to destroy lice and their eggs (nits and lice are killed at 55° C. in 
10 minutes) but not sufficiently high to damage clothing material. 
Measurements were taken at various points in the chambers, but no cold 
region could be detected. When clothing is damp the water quickly evaporates 
and the water vapours can be recognised leaving the chamber with the hot 
gases, at the vent holes. 
The interval between removing one charge and replacing it by another 
need not be longer than one minute, the unloading and loading of one truck 
is taking place while the second truck is in the disinfestor. 
Braziers properly charged with coke in the early morning require no 
further attention during the day, unless work is being continued till late in 
the afternoon, when the addition of more coke at noon is necessary. 
My thanks are due especially to Professor G. H. F. Nuttall for having 
early placed much scientific information at my disposal. The pioneer of 
Disinfestors (now of course obsolete) built in 1915, was based on the facts, 
regarding the lethal temperatures of the louse and nit, supplied to me 
by him. 
I wish also to thank Private G. A. H. Baxter, C.A.M.C., for executing 
the drawings; Privates W. H. Marshall, F. Sefton and R. A. Coward, C.A.M.C., 
have kindly prepared a working model, which may be seen in the Imperial 
War Museum. 
MATERIAL REQUIRED. 
For building disinfestor 8 ft. x 15 ft. Capacity 384 blankets per hour. Fuel consumption— 
200 lba. coke per day. 
48 sheets ... 
58 sheets ... 
9 lengths 
3 rolls or 75 yds. 
7 ft. corrugated iron 
0 ft. corrugated iron 
9 ft. each, 3 x 5 gauge rail 
18 in. trench revetting wire 
