Does Water furnish Lime to Bones. 79 through the warm mouth and throat; and because the lime they hold in solution removes acid matters from the stomach, and thus acts as a grateful medicine to the system. To abandon the use of such a water, and to drink daily in its stead one entirely free from mineral matter, so far from improving the health, may injure it. In fact, the water of a country may determine the diet of its inhabitants. The soft water of the lakes of Scotland, for instance, may have had much to do with the use of brown meal; and but for the calcareous waters of Ireland the potato could not have become a national food. Looking, therefore, at the plain teachings of all this, and considering the excellent quality of the water supplied to this metropolis, it would be folly, in my opinion, to change it for a soft water." The citizens of Dublin have recently expended nearly half a million sterling in supplying themselves with water of about two degrees of hardness, instead of the water of from fifteen to twenty-two degrees of hardness formerly in use in that city. If Dr. Letheby's view be correct, the inhabitants of Dublin may justly complain that, acting upon the advice of scientific men, they have been led to worse than useless extravagance. It seems, however, strange that the use of pure soft water could be the means of largely increasing the death-rate of a town. The ordinary food which we use contains abundance of mineral substances, with which the bony structures of the body are nourished. Even if it did not, the quantity of useful earthy matter taken into the body through the medium of water would be inadequate to subserve any useful purpose. Let us take the case of an average sample of the hard water supplied to London. It contains 16 grains of earthy salts per imperial gallon (70,000 grains weight, or 160 ounces). Few persons drink more than half a gallon of water per day, so that a person consuming that large quantity would derive from it only eight grains of earthy salts. It must be borne in mind, too, that by heating water, the hardness of which is due to the presence of calcic carbonate, a large proportion of the earthy salt is rendered insoluble. Much of the lime contained in the hard water used for domestic purposes is deposited in the tea kettles and other appliances of the household. The quantity of lime in a man of 160 lbs. weight is about one pound, and an adult daily consumes in his food at least oz. of earthy salts. As the lime contained in the bones is associated nearly altogether with phosphoric acid, and not with carbonic acid, it is evident that the chalk contained in hard waters cannot contribute, at least in an important manner, to the nutrition of the body. The apparent relation between the death rate and the nature of the water supplies in the towns mentioned by Dr. Letheby is certainly remarkable; but I think the death rates in Glasgow, Manchester, and the other towns supplied with soft water was not lower when the water furnished to them was hard. Dr. Letheby includes Dublin amongst the towns which have a very high death 80 Hard Water and Calculi. rate; and yet, until very recently, that city was supplied with water of about the degree of hardness which Dr. Letheby considers most desirable. So far as my observation extends, I am clearly of opinion that the substitution of the pure soft water of the Vartry for the hard water supplied by the canals has produced an improvement in the public health. I have received a letter upon this subject from Dr. Gairdner, late medical officer of health for the city of Glasgow, and author of an excellent work on air and water, from which I quote the following extract: "The highlanders and islanders of Scotland, who, despite many unfavourable circumstances, enjoy the credit of a low death-rate, almost all drink soft water; and I do not know a single fact showing that soft water, in the many instances in which it has now been brought into populous places, instead of hard, has in any instance led to an increased death-rate, or produced an appreciable bad effect where the other sanitary circumstances are good. "In Glasgow the whole of the west end, well-to-do population drink Loch Katrine water, and do not suffer. The death-rate of the town is affected by quite other causes." Papers have been written by Dr. Murray, of Newcastle, Dr. Cadge, of Norwich, and others, to prove that hard waters give rise to calculi in those who drink it habitually. In Norfolk calculous disease is common, and the waters in that county are very calcareous. Professor Gamgee states that sheep are very liable to calculi in the limestone districts. If calculous disease resulted from the use of hard water, then it should be very prevalent in Ireland; but such is not the case. Bad Water spreads Disease. 81 CHAPTER VIII. BAD WATER A CAUSE AND CARRIER OF DISEASE. The majority of sanitarians are of opinion that foul water is a common carrier of contagious diseases-of, at least, two of them, namely, typhoid fever and Asiatic cholera. It undoubtedly is the direct cause of non-contagious maladies such as simple diarrhoea and constipation; and not unfrequently it introduces entozoa into the bodies of men and the lower animals. Dr. Buchanan' believes that cholera and enteric fever are communicated chiefly through the medium of polluted water. Pettenkofer states that when the soil water is lowered the cholera poison diffuses itself throughout the porous soil; but, according to Buchanan, when the soil water subsides, the superficial wells become more impure from effete animal matters, and the drinking water which they supply is the direct carrier of the disease. It is evident that when the soil water is nearly up to the surface of the ground the waste matters thrown out from dwellings are carried off horizontally by the drainage; whilst, when the soil water is low, the refuse sinks into the surface wells, which thereby become polluted, and during epidemics of cholera, or endemics of enteric fever, retain the virus of those diseases. Dr. Buchanan quoted several facts to prove that typhoid fever is spread by means of polluted potable water; and he endeavours to prove that the subsidence of soil water does not affect the spread of the disease in localities supplied with water brought from pure and remote sources. I quite agree with Dr. Buchanan in regarding impure drinkable water as a common vehicle in which the germs of several zymotic diseases are carried into the body. During the last epidemic of cholera in Ireland I found that the pump water used in several localities where the disease was unusually severe contained excessive amounts of animal impurities. This was particularly the case with Arklow and Mallow. In the latter town there were few cases of the disease except in one suburb, the well water of which I found loaded with organic matter, nitrates, and nitrites. Where the disease did not prevail the water was remarkably pure. Dr. Buchanan's views are greatly strengthened by the facts set forth in Ballot's report on the spread of cholera in Holland; for that author has shown that in every town in the Netherlands where rain water alone was drank there were either no cases of cholera or a few isolated ones. On the other hand, where wells and canals furnished the water of towns or villages, the disease prevailed. Pettenkofer himself does not deny the fact that cholera and typhoid fever are occasionally contracted by drinking impure water. In November, 1869, I had the pleasure of conversing 1 Medical Times and Gazette, March 12th, 1870. 82 Cholera propagated by Water. with Professor Pettenkofer upon this and other subjects, and he stated that he believed cholera was occasionally communicated through the agency of potable water, but that the general spread of the disease was not through that channel. Dr. Bryden, of the Bengal army, has published a voluminous report on the outbreak of cholera in Northern India in 1866-68. Some of the facts mentioned in this report are strongly in favour of the theory of the general propagation of cholera by means of impure water. Whilst the water-tanks are fouled by dipping clothes into them and bathing in them, and the supplies are drying up, the disease increases rapidly; but when the tanks are cleaned out and refilled with pure rain water the cholera vanishes, and does not reappear during the time that rain keeps the tanks full of water. The history of the last epidemic of cholera in Europe appears to me to prove clearly that cholera is very frequently communicated through the medium of potable water. Letheby doubts that water had much to do with the spread of cholera in London during the late outbreak, but the great majority of health officers of the metropolis hold an opposite opinion. In an elaborate report, prepared by Dr. A. M. Ballot, of Rotterdam, voluminous evidence is produced to prove that cholera was propagated throughout Holland chiefly by means of polluted water. Dr. Ballot's conclusions are as follows: 1. Our country is highly affected by the cholera at every epidemic, chiefly in those parts where they drink water directly from the rivers and canals, or from the ground saturated with sewerage matters. 2. In places where rain water is generally drank the disease is by far less violent. 3. Places where there is no other drinkable water but rain water are not affected by the epidemic: the single cases occurring there are imported. 4. When places affected by the cholera were supplied with pure water instead of the vitiated water the disease disappeared. The use of ordinary hard water probably predisposes persons to contract cholera when the disease is prevalent; but water containing the actual virus of cholera is, of course, that by means of which the disease is chiefly propagated. In the "Second Annual Report of the State Board of Health of Massachusetts, January, 1871," the subject of the causes of typhoid fever is treated at considerable length. Inquiries were made from medical men in 163 towns of the State, and their replies occupy sixty pages of a large volume. The following is a tabulated statement of the leading queries and their answers:— 1. Have you observed a difference in the prevalence of this disease between houses supplied with water from wells about the premises and houses supplied with water conveyed from springs or from ponds of unquestionable purity? Yes, Replies. No difference has been remarked, Whole supply of town from wells, Typhoid spread by Water. 83 2 Can you inform us whether, at times when typhoid prevailed, the water of the wells was rising or falling, and whether it was higher or lower than the average for the year? (If your attention has not been given to the height of subsoil water as marked by the wells, will you have the kindness to note it in future epidemics, and let us know the result?) Replies. Rising after being very low, Falling, Very low, Have not observed, 11 16 36 100 3. Have you observed any connection between typhoid fever and foul soil, whether from privies, pigsties, manure heaps, or similar collections of decomposing matter lying on the ground? Yes, Replies. 79 45 39 4. Have you observed any connection between typhoid fever and putrid air, whether from rotting vegetables in cellars, bad drains, unventilated living or sleeping rooms, or from any other cause? Yes, Replies. 90 36 37 Ten towns report that typhoid fever is a disease almost unknown among them, and for this reason they can give no information. THE MORTALITY FROM TYPHOID FEVER IN THE URBAN POPULATION OF MASSACHUSETTS DURING THE LAST TEN YEARS. It appears that typhoid fever is more prevalent in the small towns in the rural districts than in the densely populated centres of manufacturing industries, although the death-rate from all causes is higher in the latter. This fact bears out to some extent the statement lately made by Dr. Stark, of Edinburgh, that the zymotics are, relatively to the number of deaths, as destructive in the country as in towns. They do not, however, sustain the theory put forth by Dr. Stark that the extirpation of zymotic diseases is beyond the power of man. It is shown in the Reports upon this |