[ 4P ] 
Elder, though preyed-onitfelf by fome infe&s, 
is, I believe, injurious to others.. Tobacco applied 
in powder is ufeful; and the tobacco plant I have 
never‘ feen attacked by any. ‘Bur fublimate ‘(as in 
the medicated tar) is the moft efficacious, where it 
ean be ufed with fafety. 
9. Have the foreign plants brought into this coun- 
try, introduced any infects peculiar to themfelves ; and 
have they afterwards become injurious ‘to any of our 
native plants ? 7 ¥ / 
10. Have you ever tried fumigating or other inftru- 
ments; for deftroying infetis; and how have they 
anfwered ?* 
General praétice induces us to conclude, that the 
{mothering of trees by burning weeds is beneficial, 
by. fuffocating infects. 
11.\ Have you ever tried, whether water mixed 
with coal-tar, will deftroy infeds either in the ground 
or on plants P+ 
* Inftruments of that fort, have been brought to confiderable 
perfection by Lioyn, tinman, No. 178, Strand, London. 
+ A refpectable naval officer has found it to anfwer completely, 
both in England and ‘in the Weft-Indies. He puts fome tar in a 
barrel, fills it with water, ftirs it well about, and in a few hours it 
will be fit for ufe.. It effectually deftroys that kind of vermin which 
attack goofeberry trees, and by merely watering the ground, it 
kills worms, grubs, &c. at a confiderable depth under the furface. 
It might’ be worth while to try it on grafs ground injured by 
|worms, ants, &e, 
This, frem its eafe and fimplicity, promifes well, and deferves 
othe fulleft trial. 
MOL. IX. R 12. In 
