SUPPOSED POISONING OF PIGS BY CONVOLVULUS. 819 
scences, externally so much like smooth nut-galls as often to 
be difficult to distinguish them unless weighted and carefully 
examined. 
These galls, however, do not contain the quantity of gallic 
acid that the Aleppo galls do. Still, we have employed them 
in making ink, and formed a fluid sufficiently black to write 
with, at the same time it wants much more than the nut-galls; 
but still we think these native galls might be utilised, and if 
so their collection would do good service, as the trees, or 
rather shrubs, for it is in this state they do mischief, are much 
injured by their presence. 
SUPPOSED POISONING OF PIGS BY THE 
COMMON CONVOLVULUS. 
By Harry Olver, M.B.C.V.S., Tamworth. 
In your editorial remarks on a case headed as above, re¬ 
ported by me in the Veterinarian of last month, you say 
that you are “ disposed to attach great importance to the pigs 
having freely partaken of the potato topsas “ they belong 
to the poisonous order Solanacece I am not at all surprised 
at your having expressed such an opinion ; but I think that 
if you had seen the crop in question you would scarcely have so 
thought, as the potato tops were quite insignificant in number, 
compared with the convolvulus with which they were mixed. 
The tops, moreover, were not green, unripe, and watery, at 
least not to the extent one would naturally suppose. They 
were the tops of that very early potato the ashleaf-kidney. 
When growing with the convolvulus they could scarcely be 
seen. 
For these reasons it appears to me to be difficult to under¬ 
stand how the comparatively small quantity of potato tops 
should have had such an unusually deleterious effect, espe¬ 
cially when we know that the pigs, contrary to their usual 
habits, had partaken of such a large quantity of the convol¬ 
vulus. 
I have been induced to add these further particulars in 
consequence of your remark, that from your present amount 
of information you were inclined to hold the opinion that 
the potato tops were the cause of death. The relation of the 
case will, I hope, be the means of our finding out whether 
or not the common convolvulus is poisonous to animals. 
