482 
Combating Lousiness 
has been attained is one that has been in use for some time in 
Boulogne. I am indebted to Captain C. G. L. Wolf, R.A.M.C., for 
information concerning the method. The principle consists in using 
pure chemical substances whose melting points we know are constant. 
Mallic acid was employed in Boulogne. The main thing is that the sub¬ 
stance should be cheap, easily procurable, and in no way dangerous. 
The substance is mixed with a minute quantity of any available 
dry aniline dye which need not be pure. When the substance melts it 
promptly dissolves the dye. If a colourless substance is mixed with a 
finely divided dye, the mixture appears almost colourless but almost 
instantly takes on the colour of the dye when it melts, bright blue, green, 
red, or otherwise. I would suggest, therefore, where it is desired to record 
different temperatures, that different substances be used in conjunction 
with different dyes. The substance mixed with dye is placed in small 
glass tubes sealed so that they are rounded off at both ends, measuring 
ca. 5 cm. in length with a calibre of 0-5 cm. or less. The following list 
of melting points may prove useful, any chemist should be able to 
amplify it to suit particular requirements. 
Melting Points ° C. 
63° Cumidin, 1, 2, 4, 5 
60° Margaric acid 
100° Maliic acid 
82° Glucose 
76° Urea 
70° Stearic acid 
or Paraiodonaline 
,, Dinitrotoluol, 1, 2, 4 
,, Dimethylhydrochinon 
,, Myristic acid 
55-56° Azotoluol 
54° Benzylidine aniline 
Faulty Methods and common sources of failure. 
As common sources of failure in hot-air and steam disinfestation in the 
army may be reckoned the following factors: 
1. That individual men and their effects escape disinfestation and con¬ 
sequently serve as carriers and disseminators of lice to their cleaned com¬ 
panions. 
2. That every verminous article belonging to every man has not been 
treated, with the result that some men become reinfested through wear¬ 
ing their own (or borrowed) untreated clothing perchance carried in the 
kitbag. Cardigans are likely to escape disinfestation and there may be 
a lack of clean change of garment for every man; underclothes but not 
the outer garments may have been treated, etc. The bed outfit, great¬ 
coat, even the cap and kitbag may harbour lice. 
3. That the mens bodies have continued to harbour lice. 
4. That the personnel handling infested effects do not follow the rule 
of wearing different outer garments (over-alls and hoods) when dealing 
