• [ 37i ] 
Lemma IV. The heterogeneous Subftances which are 
commonly mixed with white Salt, render it lefs 
proper for preferving Provifions, than it would 
be if feparated from them. 
After having fully confider’d the foregoing, our 
Author gives a Method of preparing a Kind of 
white Salt proper for curing Fifii, Fle'fh, and other 
Provifions; likewife a Method of refining Salt; but 
for thefe I muft refer you to the Work itfelf, as 
Well as for the Tables, wherein the feveral Expences 
attending thefe Operations are minutely confider’d. 
Mod of the Fads referred to in thefe Difqui- 
fitions are fuch, as the conftant Pradice of thofe 
who make Salt fufficiently warrants us to rely up- 
on for true and certain ; or elfe, they are the Ob- 
fervations of judicious Salt-Officers, daily converfant 
in thefe Matters, or of curious and inquifitive Na- 
vigators, Merchants, Travellers, and Naturalifts ; or, 
laftly, the Experiments of many learned Phyficians, 
Chemifts, and Philofophers : The Truth of which 
feveral Fads, though many of them have long been 
publifhed, hath never been called in Queftion. So 
that thefe Obfervations and Experiments may pro- 
bably be more relied on by the Public, than if they 
had only been made by our Author ; lincc they 
have the Teftimony of many skilful and unprejudiced 
Per foils, who could have no Notion of the Ufes to 
which they have been here applied. If therefore 
the Arguments founded upon thofe Fads fhould be 
elteemcd any-ways reafonable and fatisfadory, the 
Author prefumes to remark, that it might not be 
unworthy the Wifdom of the British Legifiature to 
dired 
