Auo. S, 1884.] 



♦ KNOWLEDGE ♦ 



119 



tlie collection of rain-water, which may be subject to all 

 kinds of impurity ; (3) a lake-water supply, prone to peaty 

 contamination; (4) a source of soft- water derived from 

 upland surface drainage, eg., the non-calcareous parts of 

 the Coal Measures and the Millstone Grit; (3) a hard-water 

 supply, from a district like that of the basin of the Thames; 

 (G) pump-water from a well on the premises ; (7) sea- 

 water. 



Domestic requirements would entail a supply of water 

 for the garden, the kitchen, the laundry, the bath-room, 

 and the ta'ile ; and for each of tliese it is desirable to 

 procure suitable water from the most ready source, with a 

 minimum of labour and expense. All the wa.ste waters of 

 the household, such as those directly derived from the 

 surface drainage, the kitchen sink, side-gutters, ic, may 

 be conveniently stored in a special brick or stoneware 

 reservoir at the end of a garden, and there treated as 

 required for the irrigation of flowerbeds, lawns, and vege- 

 table plots. Of course, in closely crowded street-houses 

 such waters cannot be utilised, and should therefore find a 

 ready escape into the general sewerage. In like manner, 

 the waste drainage from each factory ought to be stored in 

 some suitable receptacle, where it can be freed from harmful 

 products ere it is allowed to be discharged into streams, 

 rivers, or the soil. 



The storage of snow and ice in winter reservoirs has 

 never been generally adopted because of the labour which 

 such a procedure would necessitate if carried out on a large 

 scale ; yet we think that there is scope here for country 

 residents to direct some attention to processes which would 

 secure them an ample supply of exceptionally pure water 

 <luring the colder months of the year. In a paper recently 

 read at the Society of Arts Water-Supply Conference, 

 held in the Exhibition buildings,* Mr. Baldwin Latham 

 records the opinion of Pliny that some prefer " snow-water 

 before that which eometh down in followers, and the water 

 of ice dissolved before the other of melted snow ; " and 

 that the rain, snow, and ice, are all lighter than those 

 which spring out of the earth, and ice amongst the rest 

 far lighter than any water in proportion. He also states 

 that, as the result of an extensive series of experiments, 

 upon the degree of purity of frozen waters, which he carried 

 out some years ago : "that the act of freezing may be 

 carried to such an extent as to produce in the remaining 

 water a precipitation of the salts in solution, but ice frozen 

 upon very superficial water was found very liable to have 

 the impurities frozen in it which adhered to the under sides 

 of the ice, and which became embedded in it by subsequent 

 freezing ; but water which has been largely deprived of air 

 by boiling or exposure upon being frozen, if perfectly 

 crystalline, will produce absolutely pure water. Several 

 patents have been taken out with a view to freezing sea- 

 water, so as to furnish a supply of fresh water on board 

 ship, but such processes will not compete, from an econo- 

 mical point of view, with the process of distillation." 



It is advisable in the case of waters derived from snow 

 and ice, that they should be kept in vessels of stoneware, 

 or other material not liable to be acted upon by the water. 

 Tiiere are very many waters which are looked upon as 

 objectionable, because they are too soft for storage in the 

 leaden pipes and cisterns with which the water companies 

 are wont to supply the public. A few days ago, one of our 

 correspondents addressed us with respect to the water- 

 -supply of his district. It happened at a period not far 

 distant, that the water became foul through the accession 

 of sewage, and the typhoid germ accordingly grew and mul- 



* " Softening of Water," by Baldwin Latham, M.I.C.E., F.G.S., 

 &c., read July 25, 1884-, p. 7. 



tiplied in its strength to an alarming degree. Steps were 

 taken to remedy the evil, when fresh cause for serious 

 apprehension broke out in their mid.-t. The water-supply, 

 derived from the upland drainage of the Coal Measures and 

 the Millstone Grit, was particularly pure and soft, and, as 

 misfortune would have it, also peculiarly avid of lead. Now, 

 we are all aware that it is not the water itself which 

 attacks the lead, for soft waters dissolve metals because 

 they contain, or very soon appropriate various acids and 

 gases, which react upon the metals. Organic substances, 

 especially such humus, ulmic, or other acids, as are 

 likely to accrue from upland surface drainage, act very 

 powerfully on lead. Ox3'gen, nitrous and nitric acids, all 

 chlorides, and quicklime, also form soluble poisous with 

 lead. The nitrite of ammonia is said to be ])eculiarly active 

 when it comes into contact with lead ; and all these matters 

 are apt to obtain in soft waters. Their presence in small 

 quantities suffices to cause serious metallic cont,iniination ; 

 y ij^th of a grain in a gallon of water may be regarded as an 

 irritant poison. Only ^V'^ "^ ^ grain per gallon was dis- 

 covered in the water which had such evil efi'ects upon the 

 family of Louis Philippe in exile at Claremont, and ended 

 fatally in the case of Vatout, the celebrated librarian. 

 Carlionic acid does not form soluble salts with lead unless 

 in great excess ; and the carbonates, sulphates, and parti- 

 cularly the phosphates of lime and magnesia and alkaline 

 phosphates are comparatively harmless (Frankland). Other 

 metals are seldom used for the cons-truction of water- 

 holders ; we may, however, mention that injurious eflfects 

 may arise from zinc, copper, or iron impurities. Tin is 

 sometimes used as a wash over soft iron (recalled " block- 

 tin"), or lead, but is scarcely of any avail, since the decom 

 position of that metal may not be perceptible, and yet 

 periuit of an ingress of the soluble lead or other poison. 

 Tin salts themselves, if taken in moderately large doses,* 

 act as irritant poisons ; but, of course, in such cases, which 

 are not at all likely to happen, detection is quite easy. 



We have thus dwelt upon the metallic contamination of 

 water, because it is a vexed question to those who are con- 

 cerned with the supply of water in non-calcareous districts. 

 Such waters may be treated in either of two ways : — 

 they may be hardened to the extent of about five or six 

 degrees by the addition of lime, or the lead must be got rid 

 of in some way or another. The first-mentioned process is, 

 perhaps, the most valuable, since it brings the water to a 

 more generally useful condition from a domestic point of 

 view. The incorporation of a little lime not only prevents 

 the water from taking up lead by a()proj)riating those re- 

 agents which act upon the metal, but it also renders the 

 water more suitable for drinking. We may here state that 

 our correspondent has found that the use of the very soft 

 waters of his parish is detrimental to the healthy condition 

 of that most important apparatus in the digestive economy 

 — a thoroughly sound set of teeth ; he has, moreover, been 

 in the habit of recommending, in his lectures to the people, 

 the use of oatmeal porridge, especially amongst the young, 

 and we here embrace the opportunity to direct the attention 

 of our readers to his excellent and most wholesome advice, 

 which is, indeed, but an endorsement of the system which 

 has been adopted unconsciously, as the outcome of practical 

 experience, amongst the Scottish Highlanders from times 

 immemorial. 



The elimination of lead from poisoned waters by 



* Eighteen to twenty-foar grains of the chloride given to dogs 

 killed them with symptoms of violent vomiting and general depres- 

 sion in from one to three days. Two grains injected in the blood- 

 vascular system caused death with pronounced tetanus in fifteen 

 minutes, and peculiar tanned post-mortem appearance of the coats 

 of the stomach. 



