On preserving Fresh Water sweet . 59 
water and ammonia : so that the carbon, which is the 
only fixed principle which all of them contain, does not 
possess any property relative to that saturation. If we 
are guided by analogy, we might compare under this point 
of view the animal acids with the vegetable acids, and 
the animal fats (if there are any which contain azote) 
with the resins and vegetable oils : consequently the hy- 
drogen could not be in a sufficient quantity in the uric 
acid, for satuating the oxygen and azote which this acid 
contains, or to form water and ammonia by combining 
with these two bodies, and the contrary would take place 
in the animal fats. A numerous train of consequences 
may certainly be drawn from all the preceding results 5 
but we shall defer the further consideration of the subject 
till a future occasion. 
NO. 13. 
On preserving Fresh Water sweet during long Voyages, 
By Samuel Bentham, Esquire.* 
The Society for the Encouragement of Arts, &c. hav- 
ing thought proper to offer a premium in order to ascer- 
tain, for the use of the public, the best mode of preserving 
fresh water sweet at sea, I request you to lay before the 
Society an account of the method which I have employed 
for this purpose on board two ships, and which has been 
attended with all the success that can be reasonably ex- 
pected. 
The mode in which I conceived fresh water might be 
preserved sweet, was merely by keeping it in vessels of 
* Tilloch,vol. 12, p. 12. From the Transactions of the Society of Arts, See. 
Adelphi. London, for 1801.— The Society awarded their gold medal to Mr. Bent- 
ham for this communication . 
