February, '19] PIERCE: entomology and disease 45 



The louse is an insect of filth. It is to be controlled by cleanliness, 

 by heat, by water, by chemicals. Thus we have seen the rise of the 

 bath trains, the mobile horse-drawn and motor-drawn bath units, the 

 permanent bathing stations; we have seen efforts made to bathe whole 

 nations and their armies in order to combat louse-borne diseases. To 

 the Russians probably belong the credit for the first mobile bath units. 

 Now they exist in many diverse types. The basic principles in the 

 bath unit are that the men shall be bathed and their clothes sterilized 

 and that there shall be no contact between clean and unclean garments 

 or clean and unclean men. 



The greatest problem in sterilization of the clothes is to kill all lice 

 and vermin and all disease germs without injury to the garments, and 

 when to sterilization can be added cleansing then we have the best 

 process of all. The sterilization may be by dry heat, steam, hot water, 

 gas or chemical wash according to the available supplies. Every one 

 of the elements of sterilization has been studied more thoroughly than 

 «ver before. Steam sterilization may be accomplished in an autoclave, 

 a room, a car, a kettle, a barrel, or a laundry washing machine; by the 

 use of vacuum, or at normal, or increased pressure' in a closed cylinder, 

 or it may be applied as live or current steam. There is no question 

 about the killing value of steam. In the autoclave or sterihzation 

 cylinder the complete process requires half an hour, but we have found 

 recently that in a laundry washing machine we can kill all cooties and 

 nits with current steam in fifteen minutes, remove the garments, shake 

 them out and wear them. The problem in steam sterilization is one of 

 shrinkage, and injury to the tensile strength of the fabric. Steam un- 

 der pressure, even for a few minutes, is injurious to woolens. So also, 

 is steam at ordinary pressure in a little longer time. Current steam 

 does not shrink in fifteen minutes in the laundry wheel. Current 

 steam disinfection of whole buildings and cars has been used and en- 

 abled the rapid handling of great quantities of garments. Detailed 

 reports of wool shrinkage tests of many processes have been made as 

 a result of the louse problem. 



But steam, in whatever form, although effective, does not cleanse 

 the garments. 



Washing with boiling water and washing with insecticidal soaps have 

 been often proposed and successfully used, but it remained for the 

 Laundry Division of the Conservation and Reclamation Branch, 

 Q. M. C, to set in action a series of investigations to determine to what 

 extent the camp laundries could effectively control the louse. It has 

 been the writer's good fortune to be one of the group which investi- 

 gated all the laundry ami dry-cleaning processes with the view of ob- 



