38 



POPULAR SCIEiq"CE :N"EWS. 



[March, 1889. 



clay, mud, and other suspended matter may have on 

 the human system, it is not easy to say, but there is 

 no doubt that the presence of a turbidity makes the 

 water offensive to the eye. It may be stated once 

 for all that water is drank because it is water, and 

 that the presence of all extraneous matter, except 

 dissolved gases, which make it more palatable, is 

 unnecessary and, so far as possible, to be avoided. 

 The purer a water is, not only as to organic matter, 

 but also as to inorganic matter, the better adapted 

 is it for drinking. 



TOTAL SOLIDS. 



This determination shows the entire amount of 

 solid matter obtained by evaporating to dryness a 

 known volume of the filtered water. It is usually 

 expressed in grains per gallon. No fixed limits can 

 be given, as waters vary greatly. It is now thought 

 that the less solids a water contains in solution, the 

 better adapted it is for drinking purposes. The 

 total solids should be as low as possible. The fol- 

 lowing statement of Prof Charles Mayr expresses 

 this clearly. 



" Those who have never drank pure water do not 

 realize what an effect such water has upon the kid- 

 neys ; its effect is better than that of acetates, ni- 

 trates, opiates or alcohol, and for people with ten- 

 dency to kidney diseases or dropsy, there is no bet- 

 ter drug than pure water. Of the thousands of 

 chemical compounds and waste products found in 

 the human system, many require pure water for 

 their solution and elimination ; and water as over- 

 loaded with salts as average well water will not 

 work satisfactorilv." 



CHLORIDES. 



All sewage, particularly urine, contains a large 

 amount of sodium chloride (common salt) and 

 therefore water which is contaminated by sewage 

 will have an undue amount of chlorides present. 

 This determination has great value in showing the 

 probable presence or absence of sewage contamina- 

 tions in cases where the influx of tide-water is not 

 to be feared, or where there is not known to be a 

 large amount of chlorides in the soil. 



ALBUMINOID AMMONIA. 



Experimental science has established the fact that 

 a large number of diseases are communicated from 

 one person to another by means of minute organ- 

 isms known as microbes, bacteria, bacilli, microcci, 

 etc., or, more popularly, as germs. The exact de- 

 scriptions of these minute organisms, as well as an 

 explanation of their modes of development and re- 

 production, formation of spores, etc., interesting' 

 and important as they are, would carry us beyond 

 the limits of this report. The various parts of the 

 human organism afford these seeds of disease a fer- 

 tile spot in which to take up their abode and grow. 

 The diseased state of a patient is, then, in many 

 cases, merely the functional disorders arising from 

 the presence and development of certain other forms 

 of life at his expense. These disturbances may 

 arise from the mechanical irritation resulting from 

 the presence of the organisms, and also from the 

 poisonous action of the substances produced by 

 their growth, their excreta, if the term is permissi- 

 ble. It is a struggle for existence, a survival of the 

 ones best adapted to the conditions about them. If 

 the patient dies, the disease organisms are trium- 

 phant; if he recovers, they are vanquished. In 

 many cases it is a bitter fight, and a long time may 

 elapse before one can tell which will win. ^ 



To consider the details of this subject would lead 

 us far away from the matter in hand, for we wish to 

 simply explain the relations of disease to water-sup- 

 ply. The communicability of disease, as in cases 

 of small-pox, scarlet fever, diphtheria, etc., is well 

 understood by the public. The germs or virus of 

 these diseases come in contact with the proper mem- I 



branes and proceed at once to develop and cause 

 the specific functional disturbances known as the 

 disease. We have good evidence to show that dis- 

 eases can also be communicated by water, if the 

 water contain their germs. These germs, like all 

 forms of organisms, require nutriment for their 

 growth and development, and their most necessary 

 food is albuminous matter. 



When the remains of animal and plant life, ex- 

 creta, and many manufacturing wastes, are allowed 

 to remain in water, it becomes polluted by sub- 

 stances which belong to the classes of albumens 

 and gelatines, and which for the sake of conveni- 

 ence is called albuminoid matter. These substances 

 are distinguished by the ease with which they de- 

 compose or putrefy, producing, in so doing, am- 

 monia, nitrites, nitrates, and nitrogenous organic 

 substances, depending on the nature, extent, and 

 duration of the decomposition. These albuminoid 

 matters constitute the principal food of the myriads 

 of germs which exist in water, and which will grow 

 and reproduce with almost inconceivable rapidity, 

 if provided with a sufficient quantity of nutriment. 

 Some of these minute forms of life (bacteria, bac- 

 illi, microcci, etc.), as has been explained, are dis- 

 ease-germs (pathogenic microbes), while others 

 have no harmful effect, so far as we know, upon the 

 drinkers of the water. 



There are myriads of these harmless microbes 

 which act as scavengers, and consume the albumin- 

 oid matters in water, thus purifying it. It is to 

 their work that we are indebted for much of the self- 

 purification. 



These disease germs and nitrogenous organic 

 substances may cause disease in persons drinking 

 the water containing them. In themselves, the al- 

 buminoid matters may not be poisonous, or even 

 deleterious, as they are, without doubt, digested as 

 any other similar matters. But their presence in 

 any considerable amount, renders the water capable 

 of supporting germ-life, and hence it requires but 

 the impregnation with the proper disease-germs, to 

 become in an extremely short space of time filled 

 with countless swarms of these organisms, and thus 

 be in a condition to convey and impart diseases 

 with frightful efficacy. 



A polluted water may, then, so far as its rela- 

 tions to germ-life are concerned, resemble a pow- 

 der-magazine, not unsafe until a spark happens to 

 fall in it. Thus in the town of Plymouth, Pa., the 

 water of the reservoir, which was not in a good con- 

 dition as to freedom from organic impurity, became 

 impregnated by the excreta of a. typhoid patient, 

 and hundreds of cases of typhoid developed among 

 those who drank the water. A similar case occurred 

 on a smaller scale in the village of Lausanne in 

 Switzerland, the water-supply becoming impreg- 

 nated by the dejecta of a typhoid patient and im- 

 parting the disease to many persons who drank 

 well-water. Numerous cases of a similar nature 

 could be cited as to the danger from contaminated 

 wells. In fact, it is safe to say that, as a rule, all 

 wells in cities are unsafe, or at least should never 

 be used for potable purposes until proved safe by 

 the most searching analysis. On the other hand, if 

 a water is free from germ-life nutriment, any germs 

 that may get into it, will find it difficult to thrive, 

 and will be more liable to be destroyed bj' the nu- 

 merous agencies that are continually exerted to ef- 

 fect their destruction. 



The nitrogenous organic substances which re- 

 sult from the putrefaction and decomposition of al- 

 buminoid substances are often extremely poisonous. 

 Many of these substances belong to the class of al- 

 kaloids known as " Ptomaines," or cadaveric alka- 

 loids, the name being given more particularly to 

 certain substances wl^Jch are formed during the pu- 



trefaction of dead bodies. Some of these ptomaines 

 are found in the excreta, and are the normal re- 

 sults of life. Others are produced as a result of dis- 

 ease. These substances, when present in water, 

 may produce bowel-troubles and other functional 

 disorders, if not specific diseases, in those who drink 

 the water. Thus, substances have been obtained 

 by the distillation of city well-waters, that produce 

 severe bowel complaints. A great number of cases 

 could be cited in which the introduction of sewage 

 into the drinking water has caused disease. The 

 liquid in which the cholera bacillis has been grown, 

 contains a poison which, when properly applied, 

 produces a disorder which is, or greatly resembles, 

 cholera. 



The discovery of the alkaloid formed in stale 

 milk,Tyrotoxicon (thought now to bediazobenzene), 

 shows the probable cause of the prevalence of chol- 

 era infantum and " summer complaint." 



There are numerous fresh-water plants, as Alga;, 

 Sponges, etc., as well as parts of land plants, 

 leaves, buds, etc., which, when putrefying in water, 

 may increase the albuminoid ammonia, and thus 

 cause the water to assume a dangerous receptivity 

 for disease germs, aside from any specifically delete- 

 rious action that the products of the decomposition 

 may themselves exert. The death and decay of 

 myriads of animalcules and microscopic eggs may 

 also produce a decided increase in the amount of 

 albuminoid matter. 



The determination known as "albuminoid ammo- 

 nia" represents the amount of ammonia that can be 

 obtained from the albuminoid matters present in a 

 water. It depends upon the fact that albuminoid 

 substances, when heated with an alkaline solution of 

 potassium permanganate, are decomposed, and give 

 off nitrogen as ammonia. As a general rule, chem- 

 ists consider that the less albuminoid ammonia a 

 water contains the better it is. The presence of 

 o. 10 parts of albuminoid ammonia per million is 

 looked upon as a very suspicious sign, and when the 

 amount reaches 0.15 parts per million it is usual to 

 condemn the water, especially if the nitrates and 

 nitrites are present, indicating that fermentation is, 

 or has been, active. 



FREE AMMONIA. 



Free ammonia is ammonia existing already formad 

 in the water. It may be free, or combined as ammo- 

 nia salts. When unaccompanied by any consider- 

 able amount of albuminoid ammonia, free ammonia 

 indicates the presence of some manufacturing 

 waste, or recent addition of rain, snow, etc., or inor- 

 ganic substances containing ammonia salts, and is 

 of no particular importance. When accompanied 

 by albuminoid ammonia, it indicates that some of 

 the albuminoid ammonia has decomposed, and the 

 water must then be examined with care. When 

 accompanied by albuminoid ammonia and high 

 chlorides, it indicates pollution by urine. 



NITRITES AND NITRATES. 



When albuminoid matters are oxidized they form 

 nitrites, and when further oxidized the nitrites pass 

 into nitrates. Certain minute organisms have also 

 the power to reduce nitrates back to nitrites and 

 ammonia. If albuminoid matters are absent, ni- 

 trates and nitrites indicate that the organic matters 

 have all been oxidized. Their presence may or may 

 not be of importance, depending on the location 

 and source of the water, and upon the nature and 

 amounts of the other constituents. As a rule, ni- 

 trites are supposed to indicate that the oxidation of 

 the organic matter is imperfect and recent. Their 

 presence is, therefore, a danger signal. Whenever 

 nitrates or nitrites are detected in any quantity, a 

 searching examination should always be made, not 

 alone of the water, but of its source and surroundings. 

 ( Concluded in next number. ) 



