[Water supply of towns].

Date:
[1856]
Catalogue details

Licence: Public Domain Mark

Credit: [Water supply of towns]. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    7/32 (page 7)
    Of the neutral salts of lime, the chief instance is sulphate of lime or gypsiun. The important distinction between the bicarbonate and the sulphate Hes m the fact, that the fu-st, the bicarbonate, may be in great part precipitated by boihng; whereas the second, the sulphate, cannot be so precipitated. The hardening quaUty of the one is therefore curable by a simple process, whereas the other is not affected by the same process Of the two kmds of impurities, the chalk is much less objectionable than the gypsiun. The river Thames and its tributaries, and the shallow sprmgs of the London basm, are chalk waters, and aU of them may lose upwards of two-thii-ds of their chalk and of their hardness by prolonged boUing The salts of Inne are chiefly injurious on account of then- givmg to water the weU-known quality termed hardness, of which we shall aftei-wards speak. ^0 bad effect on the human system can with certainty be attributed to hme occm-rmg by itself in any water; but the notion sometimes enter- tamed, that this sa t IS either indispensable or salutary in the water taken mto the anunal body, is without the smaUest foundation The other class of salts commg imder the head of earthy salts are salts of ma^7«e.za. Magnesia IS apt to be present m smaU quantity along with chalk and other sa ts of hme; when it exists in any large proportiorS determmes a very distmet species of water, of which examples have been found in Leicester and Birmingham. Magnesia does not produce haiXess W ?L T ''^f '^ ^'^ ^^■'^^^^^^ ; ^ tl^e company of hme It sometmies does not occasion the consumption of more soap but only causes the soap-suds to curdle. This curdling of the soap rTndeS such watei^ particularly .mfit for the washing of clothes ^ Although there is the same uncertainty as to the'positive effects of magnesian waters on the anhnal system that there is iS resnert to Lf waters, yet as salts of magnesia m large doses are ^^ol^o act 2Vow S bufsir^fS^^^ Dut piobably oi a different kmd, m the small doses occim-me m an ordinnr^ magnesian water. A recent observation by Q^v^y^s TZtZ^ J -^ that magnesia is the characteristic in rediL of Wprf ? ^1. phjsician, have been mstrniifnf^l ,•„ ?„ t ■ f.'™ °' s™! mi^ttet in solut on, the salt springs of vmL^^^^ZL. r'™'? m these salts have anreffSfte hL„f 7 'l ^one of aU i. ve,, ha.,, .He o^* n« te Stin Slf taUofhe'?, V' ^ths,i.eS:»„sr:^t^^^^^^