42 
[ 302 ] 
of applying it to the extreme branches. Mr. Walsh attempts to 
explain why oily applications are more effectual than washes, by 
saying that nature has made the scales of the Bark-louse water¬ 
tight, but did not think it necessary to make them oil-tight. It is 
a sufficient explanation, and I think a more probable one, that 
greasy applications destroy all life beneath the scales, simply by 
rendering them impervious to the air. 
There is one application from which I had been led to expect 
the most satisfactory results from the strong testimony I had heard 
in its favor, and this is fish brine—being the refuse liquid in 
which mackerel and other fish have been pickeled. This possesses 
two of the essentials of a universal remedy, namely cheapness 
and a liquid consistency, so that it can be thrown with a syringe 
over all parts of a tree. I visited the orchard of Mr. John Bobson 
of Galena, and saw the trees upon which the experiment with this 
substance was, I believe, first made, some three or tour years ago 
and about which a good deal was said at the time. It was assertec 
that the scales peeled off from the branches to which it was ap 
plied, leaving the bark uninjured. I found the trees in a clear 
and healthy condition, but some doubt was thrown over the specia 
efficacy of the application, by the fact that other trees standing 
near them, and which had been treated with common alkaline 
washes, were about equally clean. I made some experiment 
with this remedy upon some infested trees in my garden, abou 
mid-summer, after the scales had become fully formed, but a littl 
before the time of depositing eggs, by dipping the ends of th 
branches into a solution, such as Mr. Bobson made use of, namely 
one pint of the brine to two gallons of water. If the applicatio 
were effectual it would of course arrest all future development c 
the insects beneath the scales, and consequently no eggs would b 
found deposited. All such experiments have been rendered ver 
unsatisfactory the present season by the almost universal destrui 
tion of the bark lice and their eggs, as previously related, by pan 
sites. But truth compels me to state that I certainly found scab 
filled with sound eggs on the branches thus treated, very fev 
indeed, but about as many as the Chalcides and other parasib 
had left on the other branches. I suspect that whatever virtv 
the fish brine may be found to possess, is due to the oil with whic 
it is largely impregnated. And even in this point of view 
may prove to be a valuable remedy by furnishing a cheap aD 
