AA 
is most commonly softer than ‘spring’ 
water, and” harder than’ rain-water. 
This is the case ‘with the water ‘in 
question. It contains a very “Tittle 
sulphate of Time, and some ‘carbonate 5 
but only one-half of the earthy matter 
that the above-mentioned pump-water 
contains. It curdles a little with soap, 
but gives no precipitate with lime-wa- 
ter. It contains about one grain of 
earthy salts in 4000 of water. 
When spring-water contains super- 
carbonate of lime, boiling it precipi- 
tates the greater part of the carbonate, 
and expels the excess of acid: Hence 
the furring of pans and tea-kettles with 
this kind of water. By boiling the 
water it is of course rendered much 
softer than before. It may then be 
used for washing, scarcely curdling 
soap; but it still contains about one- 
third of the earthy salt, and gives 
milkiness with acetate of lead. Ifa 
water contain only sulphate of lime, 
boiling does not, f apprehend, soften 
it at all. 
‘When spring-water is used by ma- 
nufacturers for washing, &c. it is 
advantageous to have it some time 
exposed to the atmosphere, in a reser- 
voir with a large surlace. This expo- 
sition suffers the carbonic acid in part 
to escape, and the carbonate of lime 
to precipitate; and in some degree 
supersedes the necessity of boiling the 
water. The more any spring is drawn 
from, the softer the water becomes, it 
should seem. I have this morning 
examined a spring, which yields many 
thousand gallons every day. The wa- 
ter is comparatively soft ; it does not 
curdle scarcely at all with soap; it is 
very nearly as soft as the before-men- 
tioned pump-water boiled. ‘The hard- 
ness in it arises froma little sulphate of 
lime and a little carbonate. 
One of the most striking facts I 
New Patents and Mechanical Inventions. 
[June ty 
have observed is; thatall spring-water 
containing’ carbonate or supercarbo- 
nate of lime, is essentially imy-or alka= 
line ‘by the odlour tests.: °Amd this 
alkalinity isnot’ destroyed tillsome 
more’ powerful ‘acid, ‘such as the sal- 
phuric or muriatic, is added, sufficient 
to saturate the whole of the limes :In- 
deed these acids may be considered as 
sufficient’ for ‘tests of the ‘quanitity of 
lime in such waters, and nothing more 
is required than to mark the quantity 
of acid necessary to neutralize ‘the 
lime. It does not signify whether the 
spring-water is boiled or unboiled, nor 
whether it contains sulphate of lime 
along with the carbonate; it is still 
limy, in proportion to the quantity of 
carbonate of lime it contains.» Agree+ 
ably to this idea, too, I find that the 
metallic oxides, as those of iron or 
copper, are thrown down by commoir 
spring-water, just the same as by free 
lime. Notwithstanding ‘this, carbo- 
nate of lime in solution with water 
contains twice the acid that chalk or 
limestone does, I fully expected) the 
superearbonate of lime in selution to 
be acid. But it is strougly alkaline; 
and scarcely any quantity of carbonic 
acid water put to it will overcome this 
alkalinity. Pure carbonic acid water 
is, however, acid to the tests.. [could 
not be convinced of the remarkable 
fact stated in this paragraph, till IT 
actually formed supercarbonate of 
lime, by supersaturating lime- water in 
the usual way, till the liquid fron) be- 
ing milky became clear.’ It still con- 
tinued limy, and was even doubtfully 
so when two or three times the quan- 
tity of acid was added. It» should 
seem, then, to be'as impossible fo ob- 
tain a neutral carbonate of Jime; as it 
is to obtain: a neutral carbonate of 
ammonia in the sense here attached to 
the word neutral, i 
NEW PATENTS AND MECHANICAL INVENTIONS. 
——— 
To. ALEXANDER HALtBuRTON, of Haigh 
Tron-works, near Wigan, esq..for cer- 
tain Improvements in Steam Engines 
and Bowlers. 
HE pressure of steam.has hitherto 
been considered as the only cause 
of the bursting er explosion, of steam- 
engine boilers, and, consequently the 
means. of prevention have been chiefly 
confined to the improvement and regu- 
lation of the safety-valve. It will, 
however, appear, from a closer atten- 
tion to the subject, that the mere ex- 
pansive force of steam does not suffi- 
ciently account for all the phenomena. 
In many of the cases related, and in 
one which came under his own, obser- 
vation, the boilers were not only burst 
but actually raised up from their seats, 
and carried to a considerable distance, 
along with bricks and other matters at- 
tached to them, which could not haye 
taken place from the pressure of steam 
in_a boiler from which the atmosphere 
is excluded, for there it acts alike in 
all directions, upwards, downwards, 
1 and 
