and Wafer used for General Purposes. 
131 
Lake^caters. — Amongst the purest natural waters hitherto 
examined are the waters of several lakes in the north of Scot- 
land and of Cumberland. These waters contain only a small 
proportion of solid matter per gallon ; they are very soft in con- 
sequence, and excellent for washing purposes. At certain times 
of the year they get coloured by peaty matters, which, besides 
rendering them rather unsightly, give them an unpleasant taste. 
The water of Loch Katrine, which furnishes Glasgow with a 
copious supply of excellent water, has been repeatedly analvsed, 
at all periods of the year, by different chemists, and has been 
found exceedingly soft and good for general household purposes. 
I have myself analysed Loch Katrine water, as well as that 
of some other Scottish lakes, and, as illustrations of the chemi- 
cal characters of verv soft lake-waters, append the following 
analyses : — 
Composition of Water from Loch Katrine, St. Mary's Loch, and 
PoKTMORE LocH in Scotland. 
Loch 
Katriiir. 
St. Mar}''s 
Loch. 
Portmore 
Loch. 
An imperial gallon contains : — 
Silica and oxide of iron and alumina 
Total fixed constituents in grains'! 
Degree of hardness : — 
These waters further contained per gallon : 
Organic (albuminoid) ammonia.. 
Grains. 
•80 
•35 
•64 
•7y 
trace 
•10 
l-i rains. 
2 00 
•79 
■81 
•59 
trace 
•20 
Grains. 
•92 
1-93 
•45 
1^01 
trace 
•23 
2-G8 
4-39 
4-54 
l^O"' 
•003 
•010 
trace 
10' 
1-4° 
•005 
•012 
trace 
2.40 
2^0^ 
•002 
•004 
trace 
The sample of Loch Katrine water analysed by me, it will be 
seen, contained only 2J grains of fixed residue per gallon, and 
scarcely 1 grain of this residue consisted of carbonate and sul- 
phate of lime. The St. iNIary's Loch water was scarcely harder 
than that of Loch Katrine, but it was impregnated with much 
more organic matter, which gave it a yellowish colour and a 
somewhat peaty taste. The total amount of fixed residue in the 
Portmore Loch water was in round numbers 4^ grains, '38 of a 
grain of which consisted of earthy carbonates and sulphates. In 
K 2 
