[ 345 ] 
to be fully faturated, and from fume other circum- 
ftances which might perhaps with advantage be taken 
into the account, and a more accurate table compofed 
than hath hitherto been publifhed ; but as the differ- 
ences would be fmall, and might not tend to any new 
difcoveries, 1 could not periuade myfelf to be at the 
trouble of making the requifite experiments'. I 
thought it would be a more ufeful undertaking to 
o # t bi O 
determine the fpecific gravities of faturated folutions 
of various falts. In compofing the following ‘table, 
1 ufed every podible precaution the folutions were 
fully faturated, by permitting the water to red upon 
the falts for feme weeks, and frequently fhaking the 
folutions during the interval : I had fome reafons 
for chufing this method rather than the much fhorter 
one of diffolving the falts in hot water, and letting 
the folutions cool, though the event will be much 
the fame in both ways ; my balance was extremely 
fenfible, though I did not ufe any weight lefs than a 
quarter of a grain ; the water in which the falts were 
diffolved' was not \ of a grain in 890 heavier than 
diddled water ; the folutions were all of the fame 
temperature, Fahrenheit’s thermometer danding be- 
tween 41 and 42 0 during the whole time of taking 
the fpecific gravities. 
A Table exhibiting the fpecific gravities of water 
faturated with various falts. Thermometer 
41 — 42 0 , barometer 30 inches. 
Water in which the Cryd Is of tar 1,001 
falts were diff. 1,000 Arfenic 1,005 
Saturated with Borax 1,010 
quicklime 1,001 Corrof. fublim. 1,037 
Vol. LX. Y y Alum 
