USEFUL PROJECTS. 
On the use of Sea Water in Agrigul- 
ture ; fromthe Earl of Dundonald’s 
Treatise on Agriculture and Che- 
mistry. 
UT as it may happen that much 
time may elapse before-any re- 
lief ‘is granted, or any alteration 
made in the present salt laws, it be- 
comes important to consider how a 
supply of salt, or what is still more 
valuable, how a supply of sea or salt 
water may be obtained for the use of 
cattle, and the purposes of agricul- 
ture, without being subjected to the 
present duties. Previous to this ex- 
planation, it 1s proper to state some 
farther circumstances, more fully to 
impress on the mind of the farmer 
the effect which salt or sea water has 
in promoting the more full putrefac- 
tion of dung and vegetable matters, 
It is well known that ships built 
of unseasoned timber are at first 
very unhealthy. The exhalation of 
the vegetable juices of the fresh 
“wood is not the sole cause. It is 
principaily to be ascribed to the 
putrescent hepatic gas generated 
by the mixture of the vegetable 
juices with the vitriolic neutral salts 
contained in sea water, forming 
what is called bilge water. The 
smell of it i$ no less offensive, than 
its effects are’ prejudicial to the 
health of the ship’s company. When 
# new vessel happens to be tight, 
and to make little water, it is tha 
practice with all intelligent seamen, 
to sweeten the vessel’s hold and lim- 
bers, by daily letting in and pump- 
ing out a_ sufficient quantity of 
water. 
Certain gases, which are in- 
jurious to the health of animals, are 
favourable to the growth of plants : 
hepatic air is one of them; and as 
hepatic air is formed in vessels’ holds 
by the action of sea water on the 
soluble mattér-efthe wood, the same 
effect will be produced by the addi- 
tion of salt water to dung or to 
vegetable matters, ‘I'he generation 
of the hepar is to be ascribed solely 
to the vitriolic salts contained in sea 
water, and there is some reason to 
suspect, that sea salt, or muriat of 
soda, may suffer a decomposition in 
this putrefactive process, and that 
the marine acid thereof may be 
decomposed, 
The putrefaction of sea water is 
not confined to the bilge water in 
vessels, The water of the sea itself, 
in certain southern latitudes, under- 
goes a. material change, emitting, 
during long calms, a putrid offen. 
sive smell; and water intended for 
the purpose of making salt, kept too 
long in the reservoirs during sum~ 
mer, will suffer such an alteration 
in its nature, as to be rendered inca- 
pable of yielding chrystals of sea 
salt. A month or six weeks of warn, 
CP 3] 
