9 ° 
Dr. Henry's Analysis of several Varieties 
country in Europe, the means of drawing from her own in- 
ternal resources. It becomes, therefore, of much consequence 
to ascertain, whether this preference of foreign salt be founded 
on accurate experience, or be merely a matter of prejudice ; 
and, in the former case, whether any chemical difference can 
be discovered, that may explain the superiority of the one to 
the other. 
The comparative fitness of these varieties of salt for the 
curing of provisions, which has been a subject of much con- 
troversy among the parties who are interested, can be decided, 
it is obvious, in no other way, than by a careful examination 
of the evidence on both sides. Where evidence, however, is 
doubtful, and where there exists, as in this case, much con- 
trariety of testimony, it cannot be unfair to yield our belief to 
that, which best accords with the chemical and physical quali- 
ties of the substances in question. Again, if salt of British 
production, should be proved to be really inferior in chemical 
purity to foreign salt, it would be important to ascertain, as 
the basis of all attempts towards its improvement, in what, 
precisely, this inferiority consists. It seemed desirable, also, 
to examine whether any differences of chemical composition 
exist among the several varieties of home-made salt, which 
can explain their variable fitness for economical purposes. 
Such were the considerations that induced me to undertake 
an enquiry, which has occupied, for several months past, a 
large share of my leisure and attention. I began the investi- 
gation, wholly uninfluenced by any preconceived opinions on 
the subject ; and I had no motive to see the facts in any other 
than their true light, since I have no personal interest, either 
directly or remotely, in the decision of the question. 
