228 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
overcome by using a lime wash as a base, so to speak. By its aid the 
requisite mixture of bleaching-powder solution and caustic soda could 
be kept in contact with the eggs for the necessary period. 
Aphis-egg-infested shoots were treated by these means, and it was 
found that after allowing the coat to dry on and its removal by 
dilute acid the eggs were all in a shrunken and obviously dead 
condition. 
The point then arose as to whether a mixture of bleaching-powder 
and lime or caustic soda and lime would not give as good results. 
These proved, however, to have no lethal effect, and it was clearly 
necessary to have all three substances together before success could 
be obtained. 
Different eggs were found to differ in the ease with which they could 
be attacked by this mixture. Of those experimented upon, it was 
found that moth eggs were the easiest attacked, then apple-sucker, then 
aphis, and lastly red spider eggs, which seemed totally unaffected. 
Having attained success so far, experiments were next tried outside. 
As was to be expected, results were not nearly so good. Mixtures that 
were successful in the laboratory had only a partial action outside, and 
in some cases appeared to have failed altogether. In one case, when 
examined the day after application, complete failure was feared, but 
subsequent examination after a month's interval showed that every 
egg that could be seen was shrivelled. 
It is therefore possible that these mixtures go on acting for some 
time after they are applied and have dried. Rain falling on them 
would doubtless dissolve out some of the soluble substances and thus 
cause a continued though possibly feebler action. This action I 
believe to be as follows :< — The sodium hypochlorite first attacks the 
chitin of the egg-shell, rendering it more porous than before, and the 
excess of alkali then penetrates to the egg contents, causing coagulation 
of the albumen. 
The hypochlorite is, so to speak, the artillery preparation, and the 
alkali is the infantry attack. Both are necessary for success, and 
neither is effective without the other. 
It is too soon at present to ofter any decided opinion as to the 
success or failure of these bleaching-powder mixtures. Trials are in 
progress at Long Ashton, and it is hoped to obtain further information 
after another season. 
