1850. 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



255 



they would, of course, fall as precipitates to the bottom of the 

 vessel, or other enclosure in which the ivater was contained, leaving 

 the water entirely free from the hi-carbonate of lime to which its 

 hardness had in a great measure been owing. He then proceeded 

 to describe I'rofessor ('lark's system of soap-tests, for ascertaining 

 the relative degrees of hardness possessed by certain waters. He 

 remarked that hard water, as was well known, curdled soap, which 

 would not produce a lather until such hardness had been overcome. 

 Professor Clark had recommended a solution of white curd-soap in 

 spirit of wine of a certain strength to be employed in this testing. 

 This solution would at once produce a lather w ith soft water, but 

 not with hard water until a certain quantity of the solution had 

 been added to it for the purpose of counteracting the hardness: 

 when lather of a proper firmness had been gained, the amount of 

 standard solution employed to produce the effect indicated the 

 degrees of hardness of any particular water; thus a standard of 

 comparison was established, by which the choice as to different 

 sources from which it would be most advantageous to procure water 

 eould be satisfactorily determined. Professor Way then performed 

 an experiment with this soap-test, on spring-water from the chalk 

 at Croydon, in comparison with water from the Thames; the former 

 indicating a hardness of about 18°, and the latter of about 15°. 

 The operation consisted simply in adding to the water, from a 

 graduated pipette or suction tube, successive measures of the 

 solution, until the water when shaken up maintained a lather on 

 its surface for five minutes. The number of measures then indi- 

 cated the quality of the water, two soap measures being equal to 

 one degree of hardness. The process was described as easy, exact, 

 and simple; and one which might be practised by any gentleman 

 who was interested in such subjects, without spoiling eitlier his 

 furniture or carpets. It would also indicate the hardness resulting 

 from the presence of sulphate of lime, as well as that from the 

 bi-carbonate; though, as he had previously remarked, water 

 hardened by sulphate of lime offered no objection for use in steam- 

 boilers, as the sulphate by boiling did not become deposited, as w as 

 the case with the carbonate; in an economical and domestic sense, 

 however, water rendered hard by either of those salts of lime was 

 objectionable. Professor Way then observed, that Professor Clark, 

 in recommending quick lime to soften water containing the bi- 

 carbonate, advised such quantities of lime to be added as a preli- 

 minary trial by the soap-test process should indicate as being 

 requisite. Such water would, by this process, be rendered soft for 

 domestic purposes, and for steam and other boilers. The only 

 difficulty consisted in tanks being required for the due subsidence 

 of the chalk thus brought into an insoluble state in the water; 

 but that was an obstacle which would no doubt be surmounted, 

 when it was considered how great the benefit of this plan would 

 be found, not only in ordinary families but in union-houses ami 

 prisons; that it was estimated that in London alone 000,000/. every 

 year was expended in the purchase of soap, one-half of w hich was 

 vrasted in the hardness of the water; and how important a point 

 it was in the processes of bleaching, dyeing, and other staple 

 manufactures carried on at Bolton, Manchester, Bradford, and 

 other places, to have a soft water in which lime was absent; it 

 would, he thought, be well worth the while of all parties interested 

 in so important a question to make arrangements for the depositing 

 tanks required. The Professor concluded this part of his subject 

 by throwing out hints by which soft water might perhaps be artifi- 

 cially obtained on a large scale, and at little cost, where it did not 

 occur natui'ally. He remarked, that water was found by experience 

 to become softened by passing through the soil; water, only, 

 however, which was rendered hard by the bi-carbonate of lime. 

 Thames water filtered through clay made permeable by the 

 admixture of sand, was found to become as soft as by Professor 

 Clark's process. Drainage water through regularly permeable 

 stiff soils was more suitable for steam-engines than spring-water. 

 But whether water thrown over the land would by that means 

 become soft, he was not prepared to say. When, however, it was 

 considered that one acre of land received every year on an average 

 500,000 gallons of pure rain-water, sufficient for the wants of 35 

 people during that period, it might be a question whether poor sandy- 

 land or bad moor land might not be covered with flat tiles for the 

 purpose of collecting the rain-water, which might be conveyed in 

 earthen pipes to the places required for its use. He merely offered 

 this suggestion for the consideration of parties more conversant 

 than himself with the practical bearings of such an undertaking. 



II. Water for Irrigation. — Professor AVay remarked that, for the 

 purpose of irrigating, he thought that water should be hard, and 

 not soft as for other purposes: that it should contain the sulphates 

 and carbonates of potash, soda, and magnesia, including organic 



matter, as all these were substances that would be taken up and 

 retained by the land. If this view of the subject were the correct 

 one, it would follow that the water in granite districts would, from 

 its softer nature, not be so useful in irrigation as that in other dis- 

 tricts where lime and other earthy substances were dissolved by 

 the water passing through them. On a former occasion Sir John 

 Johnstone had named to the council the failure of some irrigation 

 of his from the supposed circumstance of the absence of mineral 

 and earthy matter in the water, from the water in fact being too 

 pure for the purpose. Sir John Johnstone being thus a])pealed to, 

 replied that, in the water to which Professor Way IkmI alluded, 

 there was no trace of lime w hatever. The irrigation had been laid 

 out by the late Dr. W. Smith on a thin moorland sandstone rock; 

 there was no lime whatever. Professor Way then proceeded to 

 say that, in Derbyshire, and at Bala Lake, in Wales, the water 

 was exceedingly soft and pure, but considered as unfit for irrigation. 

 He felt no doubt that irrigation would become much more general 

 than it had been; and the subject was more interesting at the 

 present time on account of the Society's ensuing country meeting 

 being about to be held in Devonshire, where irrigating operations 

 had been so successfully carried out. He should, on that occasion, 

 select specimens of the different waters, under different circum- 

 stances, for the purpose of analysis, in order that he might report, 

 as requested by the chemical committee of the Society, the result 

 of his inquiries on that interesting branch of his researches. It 

 had been found, by ascertaining from analysis the nutriment re- 

 quired by the hop-plant, that only those soils that contained phos- 

 phate of lime and potash, would be suitable for the cultivation of 

 that plant — such soils as those on the green sandstone of Sussex, 

 Kent and Surrey; and that what theory had thus prescribed as the 

 condition, practice had actually proved to be the most advan- 

 tageous in fact, the cultivation of hops having been most success- 

 fully carried out on the soils in question. He thought it would 

 also be found, analogically, that successful irrigation would pro- 

 bably be found to be confined to certain districts — namely, to the 

 limestone i)rineipally. He thought it might be a question how far 

 the influence of that operation was due to the temperature of 

 the water, or its chemical composition, or to both ; he himself 

 considered the chemical nature of the water to be the most es- 

 sential ; at the same time, he was free to confess that we had 

 all to learn upon this subject, and he trusted that an inspection 

 of the Devonshire meadows would lead to further inquiries on 

 the important questions connected with this subject. 



III. Water for Cattle. — The Professor commenced this third head 

 of his lecture by remarking that he believed it was a generally 

 observed fact, that cattle liked the water of ponds, while they 

 disliked that of limestone springs; that they preferred to quench 

 their thirst in a green offensive collection of stagnant water, rather 

 than in a running spring. In Bedfordshire he had seen cattle 

 much relish a bad water filled with confervfe and animalculae; 

 which, however, was the only water to which they happened to have 

 access. Farmers generally supposed that the cattle were fond of 

 such water, on account of the green vegetable matter it contained; 

 and a distinguished professor had explained the fact by supposing 

 such water to be "meat and drink" for the cattle. It was certain 

 they did not like hard water; and it gave a staring coat to horses 

 when they were obliged to drink it; and when it was considered 

 that water in chalk districts contained from 60 to 70 grains of 

 carbonate of lime in the gallon, while London water (which was 

 hard compared with others) contained only from 15 to 16 grains, 

 it would be obvious hovv much difference would be found to exist 

 in different waters. He regai-ded a good supply of water essen- 

 tial to health, and thought it a point of great importance to 

 ascertain the kinds of water most suit.able to the animal economy 

 under different local circumstances. Professor Way concluded his 

 lecture by expressing a hope that the members present would 

 communicate to the meeting such cases of the practical effects of 

 hard water on the health of cattle, as it had been his object, in 

 the remarks he had then made, to elicit from them. 



Filter for Sea Water.— U. Cardan lately described at the Academy of 

 Sciences a new system of filtering intended to make sea water drinkable. 

 The apparatus consists of a syphon, the long tube of which is filled witli 

 powdered charcoal. The author states that the sea-water after having 

 traversed this syphon has lost its nauseous savour, and that the saline taste 

 which remains is scarcely to be detected after it is mixed with wine. M.\I. 

 Becquerel and Pouillet are named commissioners to examine into this com- 

 munication, and we hope it will be tried at sea. 



