166 M. Darondeau's Experiments on Sea-Water, 



If we consider the proportion of the residuum left after the 

 desiccation, it will be observed, as in the preceding case, that 

 sea- water, generally, is considerably Salter at a certain depth 

 than at the surface. There is one example of the contrary in 

 the table. Notwithstanding, these results do not appear to be 

 inadmissible ; for there is a great difference between the tem- 

 perature of the water at the surface, and of that at the depth 

 of from 800 to 400 fathoms ; the equilibrium must always be 

 preserved. 



As to the quantity of air held in solution in the water, the 

 table shews that the water taken at the surface in all cases con- 

 tains a smaller proportion of air than that which is taken from 

 a certain depth, and that the difference may amount to as much 

 as to one-hundredth part of the volume of water. 



Finally, the column which indicates the composition of the 

 gas contained in each of the samples of water, shews that the 

 gas contained in the water taken from a great depth, contains 

 much more carbonic acid than is contained in water taken from 

 the surface. Does this carbonic acid exist already formed in 

 the water, or rather, does it proceed from the decomposition of 

 the flaky matter which is found in all the flasks which have 

 been filled at a great depth ? This can be determined only by 

 analysis conducted on the spot. And whatever may be the 

 result, M. Biofs apparatus will at all events be the means of 

 confirming one or other of these equally remarkable facts; 

 l^^, That sea-water at a certain depth, holds in solution a much 

 greater quantity of carbonic acid than does water taken at the 

 surface; or, 2J, That at a certain depth the water contains 

 jnany transparent animalculae ; or at least some organic matter 

 which does not exist at the surface, and which decomposes with 

 time, and takes from the air, which is held in solution in the 

 water, its oxygen, so forming carbonic acid. 



According to this latter hypothesis, the proportion^of oxygen 

 contained in the air taken from a great 'depth, should be more 

 considerable than that of the air taken from the surface-water ; 

 for, in the former case, the free oxygen and the oxygen of the 

 carbonic acid form with the contained nitrogen a much more 

 oxygenated air than the atmospherical ; whilst in the latter 

 case (that of water taken at the surface), the free oxygen and 



