On the Means of curing the Dry- Rot. 131 
* enriched the arts and sciences. Similar to Minerva, that cour- 
try accompanies him into a foreign land; she speaks for him, 
introduces him, protects him, and claims in his favour an hospi- 
tality which she has often nobly conferred. Having reached the 
end of his labours, and while relating to his countrymen the re- 
ception, the assistance, the kindness, the friendship received 
from a celebrated nation, he experiences in the expression of his 
gratitude a pleasure-so much the more pure, that he feels sensi- 
ble that all these favours were less conferred on himself, than 
through him on his country. 3 
XX. On the Means of curing the Dry-Rot. By A CornRE- 
SPONDENT. 
To Mr. Tilioch. 
’ Sir, — Onsservine in the publie papers and periodical works 
the havoc the dry-rot has made in our shipping and public and 
private buildings, and having, I presume, found out substances 
for the preservation of wood from dry-rot; I take the liberty of 
stating the composition and mode of applying them. 
First. Make a strong caustic solution in water of barilla, kelp, 
or potash, and when boiling hot, wash the parts of the wood af- 
fected with the rot. The effect of this caustic ley will be the 
destruction of the vegetating fibres. of the fungus. 
Secondly. Dissolve oxide of lead or iron in pyrolignous acid ; 
and twelve hours after the first application of the leys soak the 
wood well with this solution. A decomposition of the metallic 
liquor takes place; the acid and alkali:unite, and the oxide of 
the Jead or iron is precipitated in the pores of the wood, and, pre~ 
vents the fungus from spreading. 
Another way of preventing the rot is: first, to wash the wood 
with the pyrolignous solution of lead, and ten or twelve hours after 
to wash it with a strong solution of alum (in the proportion of 
one pound and a half of alum to one gallon of water). Y 
Since writing the above, | have seen in your Philosophical 
Magazine an Essay by Mr. Gavin Inglis, recommending sulphate 
of iron to prevent the dry-rot.. I think you will find the iron li- 
quor in my process preferable, as the alkaline solution precipi- 
tates the oxide of the metal in the pores of the wood. 1 have 
paling now in good preservation, that was put up fourteen years 
ago, with staves of old iron liquor pipes and puncheons, and never 
painted. The wood is hard, and can scarcely be cut with a 
knife ; the liquor has penetrated into the pores of the wood, and 
coutracted or filled them up. 
* ; 12 Mr. 
