SECT. II.] 
PROPERTIES OF STEAM. 
61 
92. According to the analysis of Dr. John Murray, 10,000 parts of sea water, 
of the specific gravity P029, 1 contain 
Muriate of soda 
- 220-01 = 
i 
4T 
Sulphate of soda 
- 33-16 = 
1 
TO 2 
Muriate of magnesia 
- 42-08 = 
1 
238 
Muriate of lime 
7-84 = 
1 
12 7T 
303*09 = -h 
Or 1 part of sea water contains *030309 parts of salts = ts of its weight. 
93. Now as the salts do not rise with the steam, the water in a boiler supplied 
with sea water becomes gradually more saturated, and after a certain time begins 
to deposit salt, if the means that have been invented for that purpose be not 
employed to prevent it. 2 (See Sect, hi.) And even then a certain degree of 
saturation must be allowed to take place. The following table, with the constant 
numbers for different degrees of saturation, will serve to illustrate this matter. The 
boiling point of water appears to be increased one degree by each addition of 2*6 
parts to the proportion of common salt in 100 parts of water; at least, so nearly, 
that this regular law does not materially differ from the mean results of my experi 
ments, which were made with a considerable degree of care; but it is difficult to 
make them, on account of the degree of saturation constantly varying during the 
experiment. 
1 Philosophical Magazine. 
2 On the first trip of the City of Edinburgh steam ship to Leith, in 1821, this was found to take 
place to the detriment of the boiler; and the deposit was so considerable as to require its being- 
cleared out during the passage, while the vessel proceeded under her canvas. This circumstance 
led Boulton and Watt, who manufactured the engines, to adopt a method of extracting the satu-