G. H. F. Nutt all 
435 
two instances where large thoroughly efficient steam disinfectors were 
blamed as ineffective merely because they were overloaded and the 
time of exposure was too short. The greater the load the longer the 
exposure required. The ignorance of this rudimentary matter amongst 
persons responsible in an official capacity is very regrettable because so 
general. The length of exposure required cannot be determined off-hand; 
it must be established by practical experience with standard loads as it 
varies according to the type of disinfector employed. From practical 
considerations a period of 15 minutes should be allowed to elapse after 
the thermometer has reached 100° C. in the least accessible parts of the 
articles exposed to the steam. 
References to authors cited in the foregoing section: 
Bacot, i. 1916, p. 167 —Castellani and Jackson, 1915, p. 255 —Engelhardt, 1915, 
p. 166 —Friedmann, 1916, p. 321 —Galli-Valerio, 1916, p. 41 —Giese, 1915, p. 1274— - 
Greene, 1898, p. 71 —Heymann, 18. vnr. 1915, pp. 308, 318 —Honck, 1915, p. 368 — 
Izar, 1916 —Jeanneret-Minkine, 1915, pp. 132, 183 —Kinloch, 1916, p. 789 —Kisskalt, 
ii. 1915, p. 154 —Klemperer and Zinn, 1915, p. 324 —Legendre, 1915, pp. 280-3 — 
Lelean, 1917, pp. 201, 111-115 —Noeller, 1915 —Nuttall, unpublished experiments 
made in 1915-17 —Peacock, vn. 1916, p. 55 —Seligmami and Sokolowsky, 1915, 
pp. 962-3 —Slammers, vide note in Brit. Med. Journ. vi. 1915, p. 986 —Uhlenhuth, 
v. 1915, p. 533 —Widmann, vm. 1915, p. 293 —Wulker, 1915, p. 630 —Zucker, 1915, 
pp. 294-303. 
Practical Section. 
Regarding the methods of louse destruction by means of heat 
applied to clothing and effects 1 . 
1. Dry Heat. 
Burning infested clothing is a method having but a limited applica¬ 
tion since it can usually be applied only to worthless objects. The old 
makeshift measure of passing- a candle-flame or lighted match along 
the seams of clothing, thus singeing the fibres of the fabric to which nits 
and active lice adhere and causing them thereby to drop off, is a process 
which will only reduce the louse population temporarily since lice and 
nits are frequently hidden away in parts of the clothing which cannot 
be reached with the flame. Needless to say singeing cannot be often 
repeated without rendering the clothing unfit for wear. 
Sun-baking may be resorted to where conditions are favourable, the 
clothing being spread out on the ground and occasionally turned about 
1 The terms disinfector and disinfestation, in contrast to disinfector and disinfection, are 
used throughout in connection with louse destruction. A disinfector is necessarily a dis- 
infestor since it destroys infective microorganisms like bacteria and their spores which are 
much more resistant than lice. 
