388 Analysis of Scientific Books. 
15. Some Experiments and Researches on the Saline Contents 
of Sea Water, undertaken with a view to correct and improve 
its Chemical Analysis. By Alexander Marcet, M.D., F.R.S. 
Rouelle and Proust both suspected the existence, or occa- 
sional existence, of mercury, or of some mercurial salt, in sea- 
water, but no sample examined by Dr. Marcet was found to 
afford the slightest trace or suspicion of that metal. Nitric 
salts have been suspected in sea-water, but our author found 
none ; to determine this point, he used the following process 
suggested by Dr. Wollaston: The bittern was concentrated in 
a retort, till it began to deposit solid matter; sulphuric acid 
‘and gold leaf-were then added, and the mixture was boiled ; 
the gold-leaf was not in the least acted upon, nor was any smell 
of nitric acid perceived; but on adding the smallest quantity 
of nitric acid to the same mixture, the gold was dissolved, and 
the smell of agua regia was instantly perceived. No muriate of 
lime could be detected in sea-water, but it was found to con- 
tain carbonate of lime, muriate of ammonia, and triple sulphate 
of magnesia and potash. 
16. On the Ultimate Analysis of Vegetable and Animal Sub- 
stances. By Andrew Ure, M.D., F.R.S. 
This paper treats of one of the most abstruse and intricate 
departments of chemical science, that of determining the rela- 
tive proportions of the ultimate elements of organic bodies, 
and-we have no hesitation in pronouncing it the best essay 
which has hitherto appeared upon this very complicated sub- 
ject. Yet we must confess that we always enter upon details, 
such as are contained in Dr. Ure’s communication, with feel- 
ings of doubt and scepticism, partly from practical experience 
of the apparently insurmountable difficulties which inherently 
belong to the investigation; partly from the discordance in the 
results of our most eminent and dexterous experimenters ; 
and partly from the temptations which the atomic doctrine 
here peculiarly holds out to swerve into the regions of theory 
and hypothesis. We are at the same time willing to allow, 
that we feel infinitely more satisfied with Dr. Ure’s details, and 
more inclined to repose with confidence upon his results, than 
those of any of his predecessors in this branch of analysis ; and 
this because his details are more minute, his methods better 
devised, his repetition of experiments more frequent, and his 
attachment to speculation less glaring than theirs. 
Our author sets out with some valuable remarks relating to 
the materials employed, and more especially upon the hygro- 
metric quality of oxide of copper, and upon the mode of bring= 
ing the various organic objects of research toa state of tho- 
rough and uniform desiccation ; he then, aided by an annexed 
