摘要:

PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. THE monthly meeting of the society was held on Wednesday evening, May 4, in the Chemical Society’s Rooms, Burlington House, Piccadilly, the President (Dr. Bernard Dyer) being in the chair. The minutes of the previous meeting were read and confirmed. Mr. H. J. Lewin, analyst at the Royal Victoria Yard, Deptford, was proposed for142 THE ANALYST. election as a member of the society ; and Mr. F. Ill. Wharton, A.I.C., assistant to Ifr. Chattaway, was proposed for election as an associate. A paper was read by Dr. Matthew A . Adams, F.R.C.S., F.I.C., on ( ( Water Supply in Relation to the Maidstone Epidemic.”

ISSN:0003-2654    

DOI:10.1039/AN898230141b

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

142 THE ANALYST. WATER-SUPPLY I N RELATION TO THE MAIDSTONE EPIDEMIC. BY M. A. ADAMS F.R.C.S. F.I.C. (Read at the Meeting Muy 4 1898.) THE observations and experiments I have the pleasure of bringing under your notice to-night however commonplace in themselves cannot fail to have a special interest because of their association with and bearing upon an epidemic of typhoid unique for its magnitude in the annals of British medicine. As it will be assumed in that which is to follow that this epidemic was the result of the drinking of water poisoned by typhoid material it is necessary in the first place that I should give at least a sketch of the facts that this assumption is based upon. For five-and-thirty years, during which I have resided in the town Maidstone has enjoyed a reputation favour-able for exemption from typhoid for the death-rate from this disease during 1879-96 (the eighteen years of my occupying the position of Medical Officer of Health) has been only 121 per million against the following rates for England and Wales and Kent respectively : (1871-75 = 374 1 ) 1876-80 = 277 1871-80 = 330 I Kent i 1881-90= 180 1881-85 = 211 Eizglaizd aid Wales ( 1886-90 = 179 1 \ Moreover during the first seven and a half months of 1897 only five cases were reported the last of these being an importation from Gibraltar so that the news of a serious outbreak which reached me whilst I was away on the Continent for my summer holiday came as a complete surprise.The first cases to be notified were 2 on Saturday September 11 next day 4 more were notified and on Monday another making a total of 7 in three days.This was the first warning of the coming storm. Inquiries were immediately set on foot to trace any possible con-nection with milk or other sorts of food. At this time no suspicion attached to the water-supply but as on the 16th 27 fresh notifications were received then the water began to be suspected. On the 17th 26 more cases occurred making altogether 64 notified in six days. These having been plotted out upon a spot map, it soon became apparent that the incidence of the disease was confined to certain parts of the town practically to the entire exclusion of all districts excepting those that were supplied by a particular branch of the public water service. Maidstone derives its water-supply from three sources as follows : 1.From chalk springs at Cossington. 2. From chalk springs at Boarley. 3 From greensand springs at Farleigh THE ANALYST. 343 The affected districts coincided absolutely with the Farleigh area of supply and as time went on this feature in the distribution of the disease became more and more noticeable as it were dissecting the town street by street and house by house in accordance with the distribution of the Farleigh water-so accurately indeed, that as a fact one small district to which I shall presently refer as the ‘‘ Special Area,” com-prising 338 houses which in the first instance we had been led to believe was supplied with Cossington water; by the incidence of this disease was discovered in reality to have been supplied for the time being through an oversight with Farleigh water.Naturally as time went on a certain amount of spreading took place into other parts of the town by the casual drinking of the Farleigh water by the inhabitants of the other two water areas and by personal contagion but the main features of its territorial distribution were maintained to the end as is demonstrated by the follow-ing completed table of incidence : COSSINGTON SUPPLY. Houses. Persons. District. Number. I Invaded. 1 Per cent. Population. Attacked. Per cenb. To West Maidstone To East Maidstone 585 12 2 -05 86 1 7 ~ 8.14 2,925 430 19 10 0.64 2.32 Tot a1 671 19 1 2.8 BOARLEY SUPPLY. 1,410 I 3 1 4.46 - -3,355 -7,050 29 -69 0.86 -0.97 To West Maidstone To East Maidstone Total 1,410 1 63 1 4.46 FARLEIGH SUPPLY.1,618 435 26-8 1,960 338 7,050 8,090 9,800 1,690 69 673 776 134 0.97 8.32 7.92 7.92 To West Maidstone To East Maidstone Special Area Tot a1 3,916 I 1,077 1 27.5 19,580 1,583 8.08 Grand Total 5,997 1 1,159 I 19.32 29,985 1,681 5.60 From which we learn that there are 5,997 houses in Maidstone supplied by the Water Company-671 of these with the Cossington water 1,410 with the Boarley water, and 3,916 with the Farleigh water. Of the 671 in the Cossington area 19 ( = 2.8 per cent.) were invaded; of the 1,410 houses in the Boarley area 63 (= 4.46 per cent.); and of the 3,916 houses in the Farleigh area 1,077 ( = 27.5 per cent.) were invaded. Then as regards persons out of a population of 3,355 in the Cossington area 29 (-0.86 per cent.) were attacked ; of the 7,050 in the Boarley area 69 ( = 0.97 per cent.) ; whilst of the 19,580 in Farleigh 1,583 (= 8.08 per cent.) were attacked.Furthermore when we break up the districts of supply into sub-districts we notice the rates of invasion of houses and attacks upon the respective populations ar 144 THE ANALYST, as irregular as can be so far as they relate to the Cossington and Boarley areas but just the reverse in their relation to the Farleigh area. For instance the rates of invasion of the houses in the Cossington sub-districts and the Boarley district were 2.05 8.14 and 4-46 whereas in the Farleigh district they were 26.8 27.9 28.1. Mark you the special area which (as already said) was originally supposed to have received its supply from the Cossington springs by the rate of the invasion of the houses led to a special investigation whereupon it was discovered that owing to a temporary exigency of the service this special area for the time being was supplied from the Farleigh springs with which service as you see by the rates it exactly corresponds.I n the same way the same contrasts are manifest in regard to the persons attacked; whilst in the Cossington and Boarley districts the rates of attack vary tremendously (0.64 per cent. 2.32 per cent. and 0.97 per cent.) in the Farleigh they are practically identical (8.32 per cent. 7.92 per cent, and 7.92 per cent.), clearly showing that whilst the agent of mischief in the Farleigh district had been equal and uniform in its operation such had not been the case in the Cossington and Boarley districts.I n other words the cause of the mischief had been the habitual drinking of the Farleigh water by the inhabitants of the Farleigh district and the casual drinking of the Farleigh water by the inhabitants of the Cossington and Boarley districts. I think I have now said enough to justify the suspicion which fell upon the Farleigh water and the suspicion having been aroused samples were collected for analysis on September 19 20 and 25. I may here remark that this Farleigh water is itself a compound water the joint produce of a number of springs derived from the Hythe beds of the lower greensand situated right and left of the river Medway, which is their natural drainage outlet.Composed simply of subsoil water these springs emerge at the junction of the greensand with the underlying Atherfield clay and have been in use for the public water-supply for very many years I n the pursuit of my official duties I have made periodical analyses of the joint product of these springs for a space of twenty-five years but until the time of the epidemic never of the individual springs separately. These periodical analyses have shown in later years at all events very great constancy of composition so that we had come to regard the Farleigh source as thoroughly trustworthy. We have still another public water-supply in Maidstone the property of the town as distinct from the property of the Water Company called the Conduit Supply. This comes from a source exactly similar to that of the Farleigh springs.A long series of periodical analyses of this water shows its composition to be practically invariable. For this reason I have made the Conduit water serve as my ‘‘ local standard,” for purity of greensand or as we say locally Ragstone water to which all waters in our neighbourhood derived from that formation if pure should strictly conform. As all the conclusions relating to the analyses which I am now about to submit to you are based upon a comparison with this local standard I have inserted the figures relating thereto in the first column of the table of results of the analyses. Before entering upon tt consideration of the figures of the analysis it is proper I should state that, to the best of my judgment the poisoning of the water commenced about August 17, and tertiiinated about September 25; that it was at its worst during the last fou THE ANALYST.145 days of August and the first four days of September ; and further that judging by the dates of attack and making allowance for the period of incubation the violence of the epidemic had long passed when the first sample of water was collected. AnaZyses of the FarZeigh Waters.-The periodical analyses which had formerly been made once a fortnight for reasons of economy were cut down by the borough authorities to once a quarter and the last occasion on which the Farleigh water was analysed previously to the outbreak was on June 25 with the following results : Total solids . . . Chlorine . . . . Nitrogen as nitrates .. . Free ammonia . . . Albuininoid ammonia . . Oxygen absorbed in a quarter of an hour Oxygen absorbed in four hours Total hardness . . . Permanent hardness . . . . Standard. 32.890 2.300 0.466 0.005 0.015 0.008 0.018 17.400 6.500 June 25. 33.900 2.500 0.570 0.010 0.010 0.009 0-012 16.800 8.000 grains per gal. pts. per mill. grains per gal. 9 9 , 9 9 T , 9 3 9 9 9 9 9 Y Y 9 9 9 7 3 9 The main difference from the standard was 1 grain per gallon in excess of total solids 0.2 of a grain chlorine and 0.1 nitric nitrogen. Though the total hardness was a shade less the permanent hardness was 18 degrees more in consequence of the increased nitrates. From a consideration of these figures I think we shall agree that the variations from the standard were but trifling and in no way calculated to create alarm.Unfortunately the quarterly arrangement was the reason of no further analysis being undertaken until after the outbreak-in fact, not until September 19 when suspicion had fallen upon the water. Then of course, careful inspection of all the springs that contributed to the Farleigh supply was immediately set on foot and samples collected for analysis from each of them. Mean-while the most suspicious of the springs so far as local appearances went were cut off. The results of the analyses of these various samples together with the cor-responding figures of the local standard are set forth in the table on pages 154 155, a comparison with which shows the totaZ solids to be in excess in almost every case, sometimes to a considerable amount.The chlorine though never a large item shows excess in a few instances but it is as often low as it is above the standard. Nitrogen, as nitrates and nitrites in every case but one shows excess often very great excess. Free ammonia was either absent or exhibited a mere trace. Albuminoid ammonia, in all but seven instances was an inconspicuous figure ; in five cases it showed in considerable but never in remarkable excess. Oxygen consumed was never in sub-stantial excess. The hardness especially the permanent hardness was practically always in excess except in the case of the Ewe11 springs. Phosphoric acid showed considerable or large excess in only about four instances. Physical Appearance .-The Tut s ham-in-Fields water alone was conspicuously at fault.I n about three other instances there was noticeable greenish opacity but nothing to attract particular attention. The appearance of the residue both before and after ignition in many instances gave occasion for remark. By far the mos 146 THE ANALYST, important and most frequent variation from the standard was the excess of nitrogen as nitrates and I invite your special attention to this feature of the analyses for reasons which will be more apparent by-and-by. For the present I must leave the chemical aspect of the question and ask you to follow me in the consideration of certain meteorological events that appear to have had a most important bearing upon the cause and method of the pollution of the water.For many years past I have recorded the daily fluctuations in the level of the subsoil-water ; these observations led me to discover the occurrence of certain unusual features concerning the fluctuations that occurred during last August exactly cor-responding with the occurrence of the typhoid outbreak. These I will endeavour to make clear to you. I n diagram No. 1 three sets of facts are exhibited by a graphic method drawn to scale. I n the lower part we have the daily record of the sub-soil-water in feet; upon this in black is seen the rainfall in inches. At the upper part of the diagram are recorded the cases of typhoid referred to the dates of attack. For the present it is my desire that your attention be confined to the lower part of the diagram to the records of the subsoil-water levels and the rainfall and the points I more particularly wish to discuss with you are the general contour of the ground-water level the factors that are instrumental in raising or depressing the level and the interpretation of certain abnormalities which as we shall see exactly coincide with and as I shall endeavour to show were instrumental in causing the epidemic.I n the first place you will observe that the ground-water level was at its highest in February and at its lowest in November that it exhibits speaking generally a more or less gentle and uniform fall during the intervening eight months, with certain interruptions about which I shall have more to say by-and-by. The rainfall which by the way was remarkably scanty-in fact the lowest recorded since 1870 being only 19.73 inches against a twenty years’ average of 25.9-was distributed in such a manner that a great part of June the whole of July and the first six days of August-the hottest part of the year-were almost rainless.Of course the level of the subsoil water is in great measure but by no means wholly, dependent upon the rainfall. Two other factors have great influence upon it viz., evaporation caused by sunshine and wind for one ; and plant-life causing absorption and dissipation for another. A critical examination of this and similar diagrams relating to other years affords evidence that the water-level is usually at its maximum height during the early months of the year and commences its descent in April, after the vernal equinox when plant-life begins to be active; and the sinking con-tinues through the summer solstice so long as light abounds and plant-life continues vigorous even in spite of rainfall until the autumnal equinox when the earth enters the winter solsticeat the end of September.Then or at the beginning of October, a rise usually sets in though such was not the case in 1897 for we find the descent continued till November 28-but last year was altogether a most exceptional year. Of course this order of events is liable to a temporary interruption and the curve is subject to more or less distinctly marked irregularities by the occurrence of rain and it is to the minor details of this matter I would now ask your special attention. Let us begin with the year.Between January 4 and 10 there was a pretty consider THE ANALYST. 147 able rainfall and its effect upon the water-level can be traced in the rise comniencing on the 8 t h ; during the last two days in January and the first five days of February a large mass of water fell and the consequent effect is far more obvious; up went the subsoil-water till it reached its maximum on February 11 ; a small sharp and temporary rise followed a sudden and copious rainfall during the first two or three days of March but in spite of the fact that March with seventeen days of rain, proved a wet month the sun having gained power a check was set upon the further rise of the ground-water. During April its fourteen days of showery weather not-withstanding down went the subsoil-water chiefly owing to the vigour of plant-life, so that by the end of May though there had then occurred a whole week of heavy rain the water-level continued to sink rapidly.On June 8 there came a very heavy fall (nine-tenths of an inch) all within a few hours but inark you only a slight im-pression is produced. The rest of June and practically the whole of July and the first six days of August were rainless; on August 7 and 8 two most momentous days for Maidstone something less than half an inch of rain fell but as a conge-quence behold the prodigious rise in the subsoil-water level. On the 15th and 17th there was more fall and the level continued to rise. On the 18th still more rain but mark that instead of a further rise the ground-water began to descend and continued to do so in spite of more rain on the 20th 24th and 26th the descent being as rapid as the previous ascent had been even though the rainfall on the 26th on one day alone was greater than that which fell on the 7th and 8th together when such an amazing effect had been produced.During the last three days of August and the first; day of September about three-quarters of an inch of rain produced another considerable though less conspicuous rising which like its precursor soon subsided. After this a marked rise could not be maintained even by the considerable rains of September 6 18 and 19 nor restored by one of the heaviest rains of the year on the 29th. Now let us look into the explanation of all this Geologically Maidstone is situated at the junction of the lower greensand with the Atherfield clay where the constituents of the two rocks mingle so that our soil and subsoil consist of sandy or clayey loam according to the circumstance of the exact situation.At this point it is essential I should remind you of a remarkable property exhibited by clay rocks. I allude to the circumstance peculiar to clay-that it expands in the moist condition and largely contracts when dry ; moreover when greatly desiccated it becomes hard as a clinker ; as a consequence in times of drought under this latter condition clay soils are liable to become fissured ; and as a fact established by personal observation, during last summer's drought I found wide cracks into which a stick could be thrust 3 feet deep into the subsoil without reaching bottom; how deep the cracks went I have no idea.With this condition of things it is obvious that the rains of August, instead of penetrating into and being absorbed by the soil and subsoil could and would tend to find a direct road through the cracks straight away into the subsoil springs, accumulating in the first instance in the cracks between the desiccated fragments without being absorbed into the mass of the soil thereby quickly though temporarily, raising the level of the ground-water that is to say in the spaces between the fragments of the cracked soil; but so soon as absorption of the water into th 148 THE ANALYST. mass of the soil took place the adventitious rise would give way to subsidence, and thereby the water level would sink as quickly as it had risen.About a fort-night later these phenomena were repeated with this difference we find that though the rainfall was much greater the effect was much less because the surface induration of the clay fragments having already been overcome by the earlier rains capillary absorption had in a measure been restored to its normal con-dition. I n connection with this branch of the subject there are many interesting points of detail that one would like to dwell upon such as a comparison of the various effects of similar rainfalls in different conditions of the soil. For example compare the rain of August 7 and 8 with the almost exactly similar fall on September 18 and 19, producing in the earlier case a tremendous rise because of the dry cracked state of the soil-in the later case when the soil was moist and the cracks had closed up, producing no sensible ef-lfect at all.But time presses and we must pass on to a consideration of the upper part of the diagram. There we have depicted the cases of typhoid according to their dates of attack. In order to make the occurrence of the two sets of events-that is to say the pathological and meteorological; the typhoid and the movements of the ground-water-comparable a proper allowance must be made for the period of incubation of typhoid fourteen days is reckoned an average period but it varies considerably. I n addition to the fourteen days for incubation, a day or two must be allowed for the water to get to the consumer so that in the diagram I have set back the typhoid manifestations sixteen days.This should bring the two sets of events approximately into relation as regards time. I t is practically certain that in the mass of cases recorded there must be some with short incubation ; of course it is impossible to distinguish between these and those of average incu-bation so that the few scattered earliest cases as they appear in the diagram are those having short incubation and consequently set too far back. Be that as it may except for the two or three earliest cases the commencement of the epidemic exactly coincides with the summit of the first rise and the acme of the great mass of the disease coincided with the summit of the second rise. These coincidences are more than curious ; surely they stand related to one another as cause and effect.Allow ine to recapitulate the facts We have a subsoil-water stored beneath a loamy clay situated in a highly-cultivated district where heavily-manured crops are grown and where many people are employed in the cultivation and gathering of fruit and hops. The surface is necessarily bestrewn with effete organic matter and exposed to casual pollution by the workpeople employed. An unusual drought occurs giving rise to cracks in the soil and subsoil. We have physical evidence of the rapid passage through to the subsoil water-level of the surface-water derived from the rains of August 7 and 8. Chemical analyses bear evidence that the ordinary natural processes of purification are in abeyance. A six days’ pause from rain follows ; polluting specific matter is retained in the cracks of the soil and subsoil hot from the summer’s sun; incubation of the putrefying and specific organisms takes place in the dark moist subterranean recesses the cultivation process being promoted by the showers that fell on the 16th 17th 18th 20th.Then comes another pause during which an abundant crop of organisms is produced followed in six and more days later by heavier rains, which carry the pathogenic products into the ground-water out by the springs THE ANALYST. 149 straight away into the public mains and as a consequence the epidemic immediately follows. I should like to make a further use of these reflections. We all know what a difficult and responsible problem the interpretation of a water analysis for sanitary purposes often is and anything that will help to a rational understanding of the natural causes of dangerous pollution is sure to be welcome.Moreover if by an appli-cation of the rationale we can lead up to a natural generalization it cannot fail to be of some use. Now the diagram before you exhibits an ideal section of soil and subsoil such as we have been contemplating. The surface is supposed to have been polluted by the deposit of effete animal matter and the idea is to represent in outline the natural processes concerned that tend for and against the purity of the water that accumulates and flows beneath. At the outset I would remind you that three distinct sets of operations are engaged in the protection of ground-water against organic pollution. First there is the action of putrefying organisms ; second the action of nitrifying organisms ; and third the action of plants.Crude complex organic matter is first broken up into simpler organic matter; this is then mineralized into nitric nitrous and carbonic acids and finally the nitrates are removed by plants. When these three operations are fully accomplished water however much polluted in the first instance in the end is rendered pure and wholesome. I n the main the several operations are executed at successively deeper situations in the soil and for convenience we may contemplate three distinct zones each the seat of its appropriate function. The uppermost we may designate the ‘‘ danger zone ”-where the putrefying organisms are at work, converting the crude animal matter into leucine tyrosine toxalbumin etc.The next we may style the ‘‘ risky zone,” where mineralization goes on but where con-version is not complete where the roots of plants take up the mineralized products but also where the harmless and the poisonous products mingle. Beneath this we come to the “safe zone,” where the water it contains is found to have been purified not only from all organic matter but also more or less completely of all of its nitrogenous products. I n Nature of course the situation of these zones is not fixed but varies according to the exigencies of the climate, as I have attempted to portray in the diagram. It follows therefore if the foregoing propositions are correct that the presence of an abundance of nitrates in subsoil-water in most cases is significant of risk because it shows the water to be derived from the ‘‘ risky zone,” and implies the possibility of its coming from the “danger zone,” and the certainty that it is at least in an unrenewed condition, charged with the products of oxidized organic pollution.Remember we are con-templating subsoil-water ; and I would here remind you that there is nothing to show that pathogenic live organisms are acted upon by the nitrifying organisms. For aught we know to the contrary these latter only act upon dead organic matter ; and so far as cholera and typhoid organisms are concerned such protection as the soil can afford is rather of the nature of filtration than destruction. I now come to the last point I wish to discuss with you; it is one that has arisen out of the ground-water observations.We are all familiar with the circumstance that disorders pro-I t appears to me the chain of causation and effect is complete 150 THE ANALYST. pagated by the fzcal pollution of water such as cholera and typhoid are very commonly though not always liable to be preceded by what is called “prempnitory diarrhEa.” This association because of its uncertain occurrence seems to be due to some as yet undiscovered extrinsic cause. In our case the epidemic was preceded by premonitory diarrhea. Suddenly before the earliest typhoid attacks occurred, the town was flooded by complaints of violent diarrhoea (see diagram No. 2) of quite a dift’erent sort from ordinary summer diarrhoea-in fact more like that produced by poisoning. I have endeavoured to obtain accurate information concerning these occurrences and certain of my medical friends have furnished me with particulars which show a correspondence as respects time between the symptoms of this illness and the first rising of the subsoil-water; but they also show that as the typhoid epidemic advanced the diarrheal attacks subsided from which it is but natural to infer that the water drunk by the people of Maidstone contained temporarily only a poisonous material capable of producing diarrhea.Now I suggest that tcrxalbumin was the cause and that this material having accuinillated on the surface of the soil and within the danger zone was washed down by the early rains of August in an unaltered condition through the risk zone without being nitrified and so into the water that was being drunk during the early and middle part of August.Having regard to the physical condition of the soil and subsoil at this time it seems quite possible ; this material being soluble we can readily understand that it would be easily and quickly washed through the subsoil and that its effects would be spent in the early stages of the epidemic. On the other hand the typhoid bacteria being particulate and probably few at the start might lodge in the dark recesses of the warm subsoil there multiply by incubation during the interval between the two uprisings of the ground-water and eventually be flushed forward by the rains that produced the second rise. This it appears to me is a reasonable explanation of the order and character of the events of the premonitory diarrhea and the subsequent explosive outburst of typhoid.Though I have no physical evidence to substantiate it this theory accurately fits in with the observed facts. The difficulty of obtaining experimental evidence I imagine would be very great nevertheless; and I think you will agree with me the problem is of sufficient interest to deserve investigation from a chemical as well as an etiological point of view. I n this record of my experiences you will readily find subjects for discussion; in order however to give a practical turn to the matter allow me to gather together in the form of propositions some of the principal points : (1) That the recorded facts unmistakably inculpate the Farleigh water with the cause of the epidemic and that the result was brought about by the unusual meteorological circumstances in the manner suggested.(2) That the medical history of the epidemic indicates the presence of two sorts of poison in the Farleigh water the one of a chemical toxic nature causing the (3) That the most conspicuous features of the chemical analyses are (a) a large excess of nitrogen as nitrates ( b ) a comparatively small excess of albuminoid ammonia (c) a remarkably small amount of oxidizable matters. (4) That this occasion affords another illustration of the impossibility of formu-premonitory diarrhea,” another of a biologic nature causing typhoid THE ANALYST. 151 lating an artificial standard for the chemical constitution of potable water that can serve as a basis upon which to found a correct judgment as to its sanitary whole someness without other considerations being taken into account.(5) That a better simpler and more natural basis is attained by the establish-ment of local standards. (6) For this purpose especially in the case of public water-supplies it is essential that frequent analyses be made at short intervals at all seasons with or without bacteriological observations. (7) That continuous observations should be made and records kept respecting the meteorological phenomena especially the movements of the subsoil-water and the rainfall these being desirable in every ease but absolutely necessary where the supply is-derived from the subsoil. (8) That apart from ordinary considerations due to the natural mineral con-stituents a water that is of stable composition is wholesome; on the other hand, instability of composition whatever the fluctuations may be due to denotes risk.(9) For the reasons adduced the presence of nitrates or nitrites among the mineral constituents unless there be some local geological explanation thereof is in-dicative of risk-past present or future. (10) That it is desirable that research should be directed to the chemical and physiological processes associated with filtration ; among other things to determine what happens to living pathogenic organisms. Are they attacked and destroyed under any and if so what circumstances? In bringing this paper to a close I must apologize for having spent so much time over the physical facts ; but if I am not mistaken they lead to considerations that have not received the attention they require.According to my view it has been too much the custom to look upon the analysis of water as having for its sole object the detection of pollution dangerous or injurious to health whereas it ought to be the chief function of the sauitarian whether he be chemist medical officer or water engineer to prevent water from becoming dangerous or injurious to anticipate pollution and give warning of the approach of such. Surely the first step in the realization of this purpose is to ascertain the mechanism so to speak of its occurrence. This communication is intended as a contribution to that end and if in any sense successful I hope it may stimulate to further observations and perhaps assist in the interpretation of the chemical results of the analysis of water for sanitary purposes.DISCUSSION. The PRESIDENT said that all of those present had probably to some extent familiarized themselves with the general subject of the Maidstone epidemic and its relation to water-supply through the abstracts of the reports of Dr. Adarns and Dr. Washbourn which had appeared in the press. He was sure however that this paper would give them a much clearer and more instructive idea of the subject. The paper no doubt raised some debateable points ; but however different individual opinions on some of the points might be it would be generally agreed that Dr. Adams deserved hearty thanks for the very lucid way in which he had presented the fact THE ANALYST. and views set forth in the paper and that he had rendered very great service to the town of Maidstone by his work in the matter.The connection between the rainfall, the subsoil water-level and the outbreak of the epidemic had been very lucidly demonstrated and the chain of evidence all through seemed to be complete. The latter part of the paper however contained matter which at the present time might be regarded as almost new. Formerly the general opinion was that the danger from drinking polluted water was due actually to poisonous organic matter. Gradually that was given up and the dangers attributable to drinking polluted water had been generally recognised to be due not to dead organic matter but to living organisms, which exercised pathogenic functions within the system. According to the view which Dr.Adarns put forward it was suggested that there was something in the older theory after all and that actually poisonous substances (presumably produced originally by micro-organisms but already existing in the water) might be introduced -“ in bulk,” as it were-into the human system instead of being developed by the bacteria after the consumption of the water. If this were really the case one would expect to get some evidence of it in the shape of a rise in organic nitrogen; and for the examination of the view held by Dr. Adams it was certainly unfortunate that there was not an analysis of the water at the earlier period during which these substances might have been present and when it could have been seen if there was an excessive quantity of alburninoid ammonia.But thanks to the zealous desire of the Maidstone Corporation to exercise small economies in order to keep down the rates they were deprived of what might have been valuable information in the examination of this particular theory. What Dr. Adams had said with regard to local standards was most important and also what he had said as to the very great value of nitrates as an indication of pollution the latter point being noteworthy in view of a recent matter in which Dr. Adarns had been concerned. Dr. Adams had lately condemned a well at Maidstone which was shown by chemical analysis to be grossly polluted and which was close to drains in the neighbourhood of several typhoid-infected houses. The magistrates sought confirmation of Dr. Adanis’s opinion in view of its being challenged by an appeal to the Government chemists, who in their report pointed out that the water as to albuminoid ammonia and oxygen absorbed compared favourably with water drawn from the London water companies, but also that it contained 1.8 grains of nitric nityogeit per gallon (equivalent to nearly 7 grains of N,O,).They stated certainly that this proportion of nitrates was ‘‘ rather high,” but that having regard to the character of the mineral constituents of the sample this did not indicate that the water was exposed to organic contamination; and they expressed their opinion that the use of the water for potable purposes was not likely to prove injurious or dangerous to health. A comparison of the water with the local standard ” for unpolluted water in the neighbourhood would surely have rendered such a report impossible.Dr. Adams had said nothing in the paper about the bacteriological side of the investigation of the Maidstone epidemic ; but Dr. Washbourn was present who had worked side by side in the matter with Dr. Adams, and any remarks which he might make from this point of view would be listened to with interest. Dr. J. W. WASHBOURN said that he thought it would be generally accepted b THE ANALYST. 153 the Society that this epideinic was produced by the Farleigh portion of the Maidstone water-supply. The evidence which Dr. Adams had brought forward in favour of that view was most conclusive. Chemical analysis had shown beyond question that the water had become polluted in some way or other with organic material and the only question likely to be discussed in this connection was as to whether the organic material was of a vegetable or animal nature.With regard to the bacteriological examination he might say that an examination was made of a large number of the springs making up the Farleigh supply. The first question to decide was whether the water contained any typhoid bacilli. The result of the examination in this direction was entirely negative and this he attributed to two facts. In the fir& place the examination was as had been pointed out by Dr. Adams undertaken at a time when it was very likely that the typhoid bacilli had disappeared and in the second place, the examination was not commenced untiI the epidemic was at its height by which time it was very likely that the pollution had passed off As the incubation period of the disease was about fourteen days the examination ought to have been made at least a fortnight if not three weeks earlier.That was probably one reason for the negative nature of the resu1t.s obtained. The other reason was no doubt the fact that the methods at present available for detecting the typhoid bacillus in contaminated water are very imperfect. He did not know of a single instance in which water suspected of conveying typhoid fever had been definitely proved to contain the typhoid bacillus. On several occasions it had been stated that typhoid bacilli bad been found in drinking-water but most of these examinations were made at a time when the methods adopted for distinguishing the typhoid bacillus were not sufficient to distinguish it from other allied bacilli.The best instance in which an examination with the object of detecting the typhoid bacillus seemed to have been carried out according to modern methods was that of experiments made by Remlinger and Schneider who found typhoid bacilli or at any rate bacilli having the characters of the typhoid bacillus in a large number of samples of water and soil. I n fact the very large number of instances in which they found the typhoid bacillus looked suspicious and the account given in the journal of the Pasteur Institute of the character of these bacilli was not suficiently detailed to enable definite conclusions to be drawn. The next step in connection with the Maidstone water was to examine and enumerate the bacteria present.The number of bacteria found in water was of itself not of very great importance though he thought that if a water was constantly found to contain a large number of bacteria it might be taken as certain that it was polluted not with animal matter necessarily but with material of some kind from the surface. The surface of the soil ccntains a large number of bacteria but the further down one goes the fewer one finds until the deepest layers are found to contain no bacteria at all. If a water was pure it would contain very few bacteria,, but a water might contain only a few bacteria and still be liable to contamination. On the other hand a fairly large number of bacteria might be found in a water which was not polluted.Water that had been stagnant for some time in a well would, when it was first pumped up contain a large number of bacteria the fact of the matter being that the bacteria had sunk to the bottom forming a sediment which would be drawn up by the first pumping. I n judging the purity of a water from th 154 bluish-green. ' MAIDSTONE Clear bluish-green. WATERWORKS CO Chlorine . Nitrogen as n i t r a t e s a n d n i -.Nvw RESULTS OF b ihpercent. upon the localstand-ard . F r e e a m -monia . Albumin o i d ammonia Oxygen Q hour . Oxygen 4 hours . Total hard-ness . Permanent hardness T w o - f o 0 t tube . Phos p h o r i c acid . . , Smell . Nil. Nil. pale-blue. greenish-blue. I I1 I 1 1 Collect-All sources, Public Hospita' Sept.20 4. Catch-pit S.E.R., Sept. 20, No. 1, Catch-p i t No. 2 , S.E. R. Sept.20 Catch-pit No. 4 S.E.R Sept. 2 _ _ 8. -~ 45.9 3-7 3.3 1.14 Catch-pit No. 5, S. E.R., Sept. 20. -9. 42.7 0.8 3.2 -1.14 t 144% Nil. *03 Catch-pit No. 3, S.E.R., 3ept. 20. ~ _ 7. 45.1 3.5 3.2 - _ _ 1.14 1 1 ing-all SOURCE. I 2::; I Tanks, ~ sources. Tut-sham-in Field, Sept. 19. 2. 39.5 3.8 2.5 _ _ ~ _ _ -Ewe11 In jectioi Tank, Sept. 19 ~_ 3. 23.2 1.5 2.0 - _ _ -. . . I I i j I Sept. 19. 5 . 40.7 4 6 2.1 1-52 + 226% Nil. *02 -00 3 *021 6. -___ -_ 40.4 5.2 2.2 1.02 t 1197 Nil. -01 so05 -017 34.3 4.0 2.5 -84 + 80% Nil.-01 -005 *018 15.6 7.8 Clear Total solids I 32.89 I 34.8 LOSS on igni- I I ; tion . 2.51 1 4.4 2.30 1 2.5 (I I + 527; Nil. *I3 -012 ,022 18.7 11.3 Green, very turbid. Mode-rate trace. Slight. kwkens + 50% Nil. -07 ,005 .017 12.7 6-3 Clear green. Slight trace. None. Black-ens. q005 i moot ,020 ! -02; *010, I -032 21.2 8.2 Green, ;lightly turbid. Slight trace. None. Mode-rate ilacken. ng and 'using. 21.3 ~ 20.4 I 10.5 i 9% Clear ' Clear reenish- / bluish-blue. I green. 10.1 8-2 Clear bluish-green. Slight trace. hTone. Slightly dackens and fuscs. Mode- ' Trace. rate ' trace.Yone. None. lackens Mode-and ; rately slight I blackens 'using. White. 1 ! Slightly ~ black ens. and f i 3 All results are given in grains per gallon excep YY'S EAST FARLEIGH SUPPLY. Tixt-sham-in. Field, Oct. 19. 155 Church End, No. 8 Catch-pit, Oct. 19. CAL ANALYSES. Kospital Wood. Catch-pit No. 9, S. E .R., Sept. 25. Ale .rch. )it 1. G, t. 25. tch-',R., Big Church. Catch-No. I , S.E.R., Sept. 25. Pi t, Church End. Catch-pit No. 8, S.E.R., Sept. 25. ~ Culvert Under- , bank. Catch-pit No. 10, S.E.R., Sept. 25. End Spring. Catch-pit X O . 11, S.E.R., Sept. 2,i. Engine-room all I sources, I less T u t - sham, Sept. 22. Ewe11 Air Pipe, Oct. 29.supply, Tut-sham-in Orchard Kov. 16. j Oct. $8. 0. 11. 12. 13. 14. 15. 1 16. 21. 1 22. 1 9 0 57 22% il. 01 006 315 1 8 3ar ish-39.6 ' 41.5 2.7 I 4.9 I 36.9 ~ 45.3 ' 49.7 ' 32.8 2.3 3.5 3.5 i 2.1 1 I 34.8 2.6 1.9 -68 + 457! Nil. -02 -003 -012 18.5 8.7 Clear bluish green. Slight trace. None. 38.5 4.9 38% 3-0 2.2 -8 9 + 90% -03 -11 -007 ,020 20.4 11.1 Bluc-green, with pended matter. Heavy trace. None. sus-I 3.2 -64 2.2 *83 I 1 i +22"/ Xil. -01 i Nil. I +780/ 4 7 3 ~ ; ' +840/:, Nil. Nil. Nil. , + 37% Nil. Nil. *005 -015 18.9 8.9 Clear bluish-+ 78% Nil. .01 -009 -017 19.3 8.8 Clear green. Mode-rate trace.None. + 37% Nil. Nil. -008 -015 + 73% -01 -17 -010 *020 22.0 8.9 Opaque brown, very dirty and bad. Heavy trace. None. + 33% Nil. *02 -007 -02 -004 -008 12.9 5.3 Pale clear blue. Mode-rate trace. IYone. *02 02 ' -01 I ! *013 .009 a005 -13 -011 .OIO1 so27 14.0 14.0 17.2 121.2 23.4 ~ 16.7 ! i 5.5 5.7 9.9 Clear green. Mode-rate trace. None. 7.2 Gray or dirty green. Slight trace. None. Mode-rately 8.4 Clear green. Slight trace. None. 10.6 Clear green. SIight trace. Kone. Pale Turbid clear blue. Very heavy trace. Norie. Fuses, and green. Large amount. None. Mode-rately black-,en. green. I :ry Slight ght trace.*ce. me. 1 None, Moqe- 1 Slightly rately / black-b h k - ens. de- Mode- Very te rate I black, ken- blacken- ~ and and ing and fuses. ;ht I slight I ng. fusing. 1 Slightly 1 Slightly Slightly llackens blackens ' blackens and and ~ and slightly )lacken$ ens. rather bad. Jlarkek. and 1 blackens fuses. ~ slight j much- and I fusing I fusing, I fiisina. 1 fiisinp I slight bad bad -a . 0 1 fusing. looking. looking I -- 1 I Albuniinoid Ammonia which are in parts per million 156 THE ANALYST, number of bacteria it contained it was necessary to be very careful although as he had said if a large number of bacteria was constantly found it might be taken that the water was bad. The character of the bacteria however was of the greatest importance.No doubt waters from different sources had their own special bacterial flora but certain bacteria might enter into water from animal excreta these bacteria mostly belonging to the group of organisms known as Bacillus coli conamunis. These bacilli were found in large numbers in the intestinal contents of almost all animals and they could be distinguished from somewhat similar bacteria which were present in pure water. The bacteria present in pure water which resembled coli were bacteria be2onging to the Aquatilis sulcutus group. They could be distinguished quite readily from coli bacilli among other points by the fact that they did not grow at the temperature of the body or only grew very feebly at that temperature. The coli bacilli on the other hand grew readily at this temperature.The intestinal contents of animals human or otherwise contained a large number of different varieties of coli some coagulating milk quickly and some slowly some producing more acid than others and so on. I n fact in all intestinal evacuations, there were to be found what were called a-typical coli bacilli which differed from the ordinary text-book description in some minor points. There was no evidence that coli ever occurred in water that had not been contaminated with animal matter. Water contaminated with vegetable matter and upland waters did not contain coli as far as was known. Whenever the coli bacillus was found in any numbers it meant contamination with animal excreta. I n saying that water contained coli bacilli he meant in fairly large numbers since animal excremental matter was very widely distributed and consequently coli bacilli were also widely distributed ; so that in examining a large quantity of water one might now and then meet with one or two colonies the occurrence of which would not be of any significance but due merely to accidental causes.A large number however say 60 per c.c. would definitely show a water to be contaminated with animal excreta such as he had found to be the case in one of the springs which supplied the Farleigh water. The presence of these coli bacilli simply meant that the water was contaminated with animal excreta. It did not necessarily indicate human excreta but it did indicate that the water was contaminated with animal excreta and that it was thus liable to contamination with typhoid material There was one other point with regard to the coli bacillus namely, the question of its pathogenic properties.There was no function possessed by the coli bacillus that varied to a greater extent than its pathogenicity. Some coli bacilli had strong pathogenic properties while others had no pathogenic properties whatever, so that this factor was of no value at all in determining whether any particular organism belonged to the coli group or not. The only point on which he disagreed with Dr. Adams was in regard to the wave of diarrhea which preceded the typhoid epidemic. He had no doubt whatever that Dr. Adams’s explanation of the rise in the subsoil water was correct and that the water had beconie contaminated with typhoid virus in the way which Dr.Adams had described and he (Dr. Washbourn) believed that the water at the same time became contaminated with the virus that produced the premonitory diarrhea. But he believed that this virus was a living micro-organism and not a chemical poison. A large quantity of a toxalbumin would nee THE ANALYST. 157 to be present in order to produce so much diarrhea and he did not know of any toxalbumin that would produce such an effect in small quantities. The more one knew about cases of (‘ food poisoning ” the more one was inclined to look upon them as due to the ingestion of bacteria and riot of toxines. He believed that the Farleigh water was contaminated both with the specific typhoid bacillus and with some form of bacterium which would produce diarrhoea arid that the reason why the diarrhaa occurred earlier was simply that the incubation period of the diarrhoea was shorter than that of typhoid fever.Dr. CHILDS rising in response to an invitation from the President said that the subject of subsoil water was one of which he had made a special study in connection with the prevalence of typhoid fever in the city of Munich during the last forty years. It would be difficult however to make any comparisons between the data that came from Munich and those obtained from a study of the epidemic at Maidstone though there was this analogy between them that in Munich as well as at Maidstone the relations between the movements of the subsoil water and the rainfall seemed to be exceedingly irregular.It could not be predicted from a previous heavy rainfall, whether there would be a large rise in the subsoil water or not. I t depended upon a good many other conditions such as those which had been mentioned by Dr. Adams, and also upon t’he previous rainfall. If the subsoil had become water-logged the rain falling upon it would cause a considerable rise; but if there had been a drought, the subsoil itself would act as a sponge and there inight be little or no rise. The whole question required a tremendous amount of elaboration and study before one could speak of these relations with any accuracy. With regard to the relations of the subsoil-water level to typhoid epidemics these had been very distinctly established in Munich whilst contrary to the experience in our own country the Munich authorities considered that there was no relation at all between the actual drinking of the water and the prevalence of typhoid fever.Pettenkofer and his school had long been convinced of this and as time went on seemed to become even more con-vinced still. But the conditions of the city of Munich were exceptional and different from those usually prevailing in this country. And although the revelations obtained there were rather extraordinary and tended to shake one’s faith in the convection of typhoid by water they could not be taken as analogous to the results generally obtained in this country. His own personal conclusion was that there were inany different ways in which typhoid fever might be conveyed. The evidence obtained in this country as to the water convection of typhoid was so strong and reached such high degrees of probability in maay instances that he thought it must be held to be conclusive in spite of the different ideas held by such a great authority as Pettenkofer.He agreed with the President in feeling grateful to Dr. Adams for emphasizing the necessity for the establishment of a local standard of purity and for proper inspection and supervision of the sources of water-supply and their surround-ings ; which latter point he (Dr. Childs) regarded as of primary importance. Mr. HEHNER said he was sure that Dr. Adams would have the Society’s sympathy in the fact that after so many years of service at Maidstone he should have been confronted with the recent typhoid epidemic coming as it did after many years of labour in the interest of the health of the district.On the other hand 158 THE ANALYST. Dr. Adams must be congratulated on the exceedingly interesting observations which he had made on the subsoil water of the district which though not appearing at first likely to lead to any useful result had now been rewarded by the brilliant deductions he had been able to make with their aid. The long series of analyses of samples of water showed conclusively that with one exception they were all polluted to a large extent. Anybody conversant with water analysis and anyone who had urged as he (MY. Hehner) had done many years ago the importance of not judging from arbitrary standards but taking as a basis the composition of the pure water of the district would agree that there was overpowering and conclusive evidence in these analyses that the samples were polluted with a nitrogenous substance which yielded nitric acid and hence almost certainly with animal matter.With this was to be compared the fact that even in the able hands of Dr. Washbourn bacteriology had failed in almost every case to afford evidence of pollution. He (Mr. Hehner) admitted of course the great difficulty of the task which had been given to Dr. Washbourn who had had to examine the water so long after the outbreak; but Dr. Adains had also been in the same position. He (Mr. Hehner) was puzzled by some of the figures given by Dr. Adams because if the history of the outbreak as gathered from the newspapers was correct the pollution was due to the accidental contamination of the soil by a limited number of people and it was difficult to under-stand how on so many days extending over some months there should have occurred such a notable increase in the nitric acid an increase which was found, not in one sample only but throughout the series.The Farleigh water was supplied to 20,000 inhabitants the average supply being about 20 gallons a day per head ; consequently an increase of 110 per cent. of the normal proportion of nitric acid meant a daily increase of 126 lb. of nitric acid which over several months would represent a good many tons and it was scarcely possible to think that a chance pollution on the surface should have been able to produce such immense chemical results. Dr. Adains’s very ingenious distinction between toxalburnin poisoning and actual bacterial poisoning struck him as somewhat bold because there appeared to be no basis for such a theory except the inference that premonitory diarrhea occurred immediately before the epidemic and before the bacilli were likely to act, a suggestion however which was not entertained by Dr.Washbourn who thought that even the poisoning usually attributed to ptomaines in tinned goods was due to bacterial causes. There was however a sharp or at any rate a fairly sharp distinc-tion between strictly chemical poisoning and bacterial poisoning. The effect of chemical poisoning was far more rapid than would be expected if bacteria had first to incubate and multiply. But as a matter of fact the products of living organisms were capable of producing powerful toxicological effects.I t might be quite possible for even a very small quantity of a substance of the nature of toxalbumin to produce the diarrhea which had been observed. Mr. ALLEN said that Dr. Adams had shown very clearly the great value to be attached to a conclusion derived from the quantity of oxidized nitrogen present in water. The Maidstone epidemic had been caused unquestionably by water that did not contain inore than the normal proportions of free and albuminoid ammonia etc., but contained a large proportion of nitrates. I t was a fact to be greatly deplored THE ANALYST. 159 that the significance of oxidized forms of nitrogen in water was systematically ignored by the writer of one of the most popular and widely-used works on water analysis.I n water analysis it was impossible to have too many data upon which to base an opinion. He would say obtain as many chemical factors as possible and, if bacteriology was likely to be of service make use of it also. He would not limit the andysis of water to any small number of tests but would have as complete an examination as possible so as to be in a position to regard the matter from every point of view. With regard to the instance in which the Government chemists, having undertaken to report upon a sample of water from a Maidstone well which was surrounded by houses infected with typhoid fever stated that the water contained 7 grains of nitric acid per gallon and yet was not even liable to con-tamination he thought it was a pity that they should have gone out of their way to express an opinion on a point wholly outside their range of information and not warranted in any way.Mr. CASSAL said that up to the present full chemical analysis supplemented by microscopic examination had been more reliable and had given more satisfactory results in water examination than bacteriology. As an aid in forming an opinion, bacteriological investigation was occasionally valuable but the information it gave never amounted to anything more than mere confirmatory evidence. I n the Maid-stone investigation in those cases where Dr. Washbourn had been able to make a positive statement Dr. Adams would have been able to speak most positively and no doubt did so even from the yield of albuminoid ammonia alone; and of course, when the nitrates also were considered there was unquestionable and indeed, crushing evidence in support of the position which Dr.Adams had taken up. There was no doubt that the detection of a large number of coli bacilli or the detection of a large number of bacteria of any kind over and above what was normally found in a given supply afforded valuable confirmatory evidence; but that was all up to the present that bacteriology had been able to do. He should like to point out that for a considerable period Dr. Adams had examined the water of his district. By this examination he was enabled to obtain what he described as his local standard and was thereby able to gauge with accuracy any change that might take place in the character of the supply; but on the ground of so-called economy the local authority decided to dispense with this measure of precaution.They and the population they were supposed to represent had been punished most severely for that action and the lesson was one which ought not to be forgotten. Mr. F. WALLIS STODDART said he had been reluctantly forced to the conclusion that the detection of the typhoid bacillus under the usual circumstances of an epidemic was impracticable. He would go even further and say that he did not think it ought to be undertaken except as a piece of scientific research. I t was desirable that something like a definition of Bacillus coli communis should be formulated. He had obtained pure cultures from the original discoverer Escherich, but the organism obtained from these pure cultures was quite different from anything that had been obtained by himself or by any of his bacteriological friends and as long as that state of affairs existed he felt some diffidence in saying that any organism was Bacillus coli or that it was derived from intestinal sources.He was obliged t THE ANALYST. support Mr. Hehner and Mr. Cassal in saying that unquestionably as a guide to the quality of ground waters there was nothing to compare with chemical analysis judiciously applied. He thought the relation of nitrates to the organic matter of sewage both dead and living was perhaps scarcely appreciated. The formation of nitrates was the outcome of a series of fermentations of dead organic matter and it had been experimentally demonstrated that the process of nitrification could be carried out to completion without apparently interfering with the vitality of any pathogenic organisms that might be present.He gathered that Dr. Adams shared the current opinion that water falling on the surface of the ground actually sank uniformly so to speak through the soil and underwent a gradual process of filtration, which resulted first in the elimination of these organisms; secondly in the produc-tion of nitric acid; and ultimately in the complete purification of the water. This, however he thought was not the case. The water travelled and was to be obtained in quantity only in natural passages either between impervious strata or through fissures in those strata. Even in the case of such a pervious medium as the chalk, the water did not pass uniformly through in bulk.I t invariably found the easiest channel to flow through and nitrification mas all the more complete as the water became more completely aerated during its flow. The very openness of the channel would permit the organisnis to travel through a considerable thickness of subsoil. From these considerations he thought it quite possible that a water like many of these samples might be quite devoid of chemically demonstrable organic matter and yet contain pathogenic organisms in an active and vigorous condition. Dr. VOELCKER while agreeing as to the desirability of local standards said that it appeared to him to be a not very easy thing to fix a proper local standard. If the standard taken was that of a doubtful source wrong conclusions would necessarily be formed.The real difficulty was to know whether the local standards adopted were really representative ones or not. Mr. Cassal had remarked that some of Dr. Adams’ samples might have been condemned on account of the albuminoid ammonia alone. He (Dr. Voelcker) would have been very sorry to do that in any case without knowing absolutely the nature of the supply. Nor could he altogether subscribe to Dr. Adams’s theory of zones. The nature of the soil seemed to have been left very much out of account. It would hardly be possible to divide all soils up into zones, and t o assume that a certain set of operations went on in one zone and not in another independently of the nature of the soil. Dr. ADAMS referring to Dr. Washbourn’s remarks with reference to the probable cause of the premonitory diarrhea that had occurred observed that this diarrhea occurred at the very commencement of the epidemic and before the typhoid really set in and ceased absolutely immediately the typhoid began.The two disorders must be totally and entirely different. The one exhibited as clearly as possible the characteristics of a chemical poisoning and the other those of a bacterial poisoning. The typhoid continued to spread over a considerable time as long in fact as the water containing the organisms was allowed to be drunk; the diarrhea on the other hand without any interposition occurred at the cornmencement of August and concluded practically within that monLh whereas the water which was believed to have been the cause m.as being freely drunk until the 26th or 28th of the followin THE ANALYST. 1 G 1 month. What he maintained was that during the whole of the dry season the putrefactive changes in the animal organic matter were going on and that these changes brought with them certain chemical results which accumulated on the surface and which being soluble were at once carried into the water when the rain fell and were thus consumed Their effect then ceased because there was no continuance of the causes which produced and therefore no reproduction of the poisonous material. If the diarrhoea had been caused by bacteria which simply differed from the typhoid organisin in having a shorter incubation period it might reasonably have been expected that such diarrhoea organisms would multiply and continue their effect in like manner with the typhoid organisms; but that was not so the diarrhoea began and was ended before the typhoid started. With regard to Mr. Stoddart’s observations he of course had in view the question of local circum-stances which must be taken into consideration in the selection of local standards; though he might remark that all the waters to which he had referred in the paper came from soils which for all practical purposes might be regarded as precisely similar

ISSN:0003-2654    

DOI:10.1039/AN8982300142

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 1 G 1 ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. Detection of Citric Acid in Vegetable Juices Wine and Milk. G. Deniges. (Rev. Chinz. AnaZyt. appl. vol. vi. [7] pp. IlO-ll2.)-The method is based on the fact that under the inffuence of manganic oxidizing agents and in an acid medium, citric acid forms with mercury a compound insoluble in presence of mercuric sulphate. I t is applied as follows : (a) Free or Combined Citric Acid in Aqueous Solutioiz.-Five C.C. of a 1 to 2 per cent. citric acid solution are heated to boiling along with 1 C.C. of mercuric sulphate -prepared from mercuric oxide 5 grammes ; concentrated sulphuric acid 20 C.C. ; water 100 c,c.-and on removing from the flame are treated with 5 to 6 drops of a 2 per cent.solution of potassium permanganate-or 1 drop if the liquid be very dilute -which decolorizes the liquid and throws down a white precipitate. This test will reveal the presence of 0-5 milligramme of citric acid. ( b ) h z Vegetable Juices.-A few drops of the juice are diluted with 4 to 5 C.C. of water and tested as above. ( c ) Small Quantities of Citric Acid in Preseme of a La>rye Amouizt of Tartaric Acid. -Five C.C. of a 2 per cent. solution of the average sample are heated with 1 C.C. of 2 per cent. perinanganate until the mixture acquires a brown tinge and disengages a, few bubbles of gas. When decoloration has set in 1 C.C. of mercuric sulphate solution is added and the whole is again heated to boiling. A decided white turbidity is obtained in presence of less than & per cent.of citric acid. ((1) IIL lk'im-Ten C.C. of wine are well shaken up with 1 to 14 grammes of lea 162 THE ANALYST. dioxide followed by 2 C.C. of mercuric sulphate solution. After filtration 5 to 6 C.C. are heated to boiling and treated with 1 drop of perrnanganate 9 additional drops being added in succession as decolorization ensues. Under this treatment normal wines give merely a very slight haze not always appearing at once due to the traces (5 to 6 centigrammes per litre) of citric acid invariably present a fact not hitherto recorded. With 0.1 gramme per litre the turbidity is pronounced and above 0.4 granirne a flocculent precipitate is formed. (e) 1 7 2 Milk-Ten C.C. of milk 2 C.C. of a 5 per cent. solution of sodium meta-phosphate and 3 C.C.of the above mercuric reagent are shaken up together and filtered the first runnings being rejected 5 to 6 C.C. heated to boiling and shaken up with successive drops of the permanganate solution. A decided white turbidity ensues after the addition of 4 or 5 drops in the case of cows’ milk and with 8 to 10 drops a flocculent white precipitate accompanied by a yellow coloration removable by hydrogen peroxide. The author has ascertained that acetic tartaric (etc.) acids glycerin gum and other substances likely to occur with citric acid do not interfere with the reaction; any excess however of chlorides bromides or iodides must be first eliminated by silver sulphate. When oxalic acid or other substance capable of reacting on mercuric sulphate is present the mixture must be first oxidized in an acetic medium by a slight excess of permanganate which is then reduced by hydrogen peroxide before proceeding to apply the test.c. s. Adulteration of Pimento. T. F. Hanausek. (Zeit. fiir UnterszLclz. der Nalzr. zind Geizzissmittei 1898 245.)-The author calls attention to the adulteration of pimento with roasted cacao husks. The adulteration may be known by the presence of homogeneous acute-angled particles of a reddish-brown colour bordered by dark brown on one side or on two opposite sides. Treatment with hot water or solution of potash yields a slimy membrane and particles may be seen composed of a spongy tissue with sclerogen. Adhering to particles of spongy parenchyma are bundles of spires. These also occur separately and contain spiral fibres often in the form of open rings.H. H. B. S. Determination of Oil of Mustard. E. Haselhoff. (Zeit. fiir Unteysuch. der Nahr. m d Geizzissmittcl 1898 235.)-The methods for the determination of oil of mustard depend upon the estimation of the sulphur or nitrogen contained in it,. Forster (Laizdzo. Versuchs. Stat. xxxv. 209) converts the oil into thiosinamin and precipitates the sulphur with mercuric oxide as mercuric sulphide. Schlicht (Zeit. anal. Chemie xxx. 661) distils with an alkaline solution of potassium permanganate reduces the excess of permanganate with alcohol and determines the sulphuric acid by barium chloride. Passon (Zeit. angzu. Chemie 1896 422) determines the nitrogen by Kjeldahl’s method. The author has made a comparative examination of these three methods as wel THE ANALYST.163 as of a modification of Schlicht’s method consist,ing in the use of bromine-water in place of potassium permanganate. The mean results are given in the following table : Amount Found \by Found by Found by present. Fijrster’s Method. S ch lich t ’s Method . Passon’s Method. Permanganate. Bromine. 96.72 95.34 95.44 96.47 95.44 According to Schuster and Mecke (Chem. Zeit. xvi. 1954) the rise in tempera-ture which takes place on milling rape-seed prior to pressing out the oil increases the percentage of oil of mustard in the seed threefold. The author’s experiments do not confirm this. In the following case a sniall increase resulted on heating to 70” C., but by no means to the extent mentioued by Schuster and Mecke : Fresh rape-seed . . . . 0.305 per cent. oil of mustard. Defatted rape-seed . . . 0.290 , > Y ,, Rape-seed heated to 70” C . . 0.347 ,, . ” H. <. B. S

ISSN:0003-2654    

DOI:10.1039/AN8982300161

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

THE ANALYST. 163 I N 0 RGA N I C ANALYSIS. Volumetric Determination of Antimony. G . Rollin. ( B e v . dz Chim. et de Pharm., 1898, February 10, p. 129; through Rev. Clzim. Awlyt. cq~pZ., vol. vi. [ 7 ] , pp. ll4,115.)-The author Eases his method, which is applicable to the sulphides and commercial oxides of the metal, on the following considerations : 1. The Mohr titration is accurate provided the solution is kept alkaline by means of a bicarbonate throughout the operation. 2. Arsenic sulphide is completely insoluble, whereas the antimony salt is soluble in coZd concentrated hydrochloric acid, and so long as the substance does not contain more than 5 parts of arsenic oxide per 100 of antimony oxide, the precipitate produced under these conditions is free from the latter metal.3. A current of air has no action on cold solutions of antimony chloride. 4. A solution of antimony in a large excess of hydrochloric acid may be boiled for a long time without loss of metal. In testing comniercial oxides of antimony, 1 gramme of substance is dissolved in 10 C.C. of hydrochloric acid of a specific gravity of 1.176, and treated with gaseous sulphuretted hydrogen to remove arsenic. The liquid being then transferred to a 250 C.C. flask and the glass rinsed with a little hydrochloric acid diluted with its own bulk of water (not more), the excess of sulphuretted hydrogen is removed by a current of air. Five grammes of tartaric acid are added, the liquid made up to the mark, and passed through a dry filter. One-tenth of this volume is taken for titration, carefully saturated with sodium bicarbonate solution, and, after adding a pinch of the solid salt and a little starch paste, is titrated with standardized iodine solution.I n the ca,se of antimony sulphide, 1-5 gramrnes are dissolved in hot concentrated164 THE ANALYST. hydrochloric acid, and, when perfectZy cold, treated by sulphuretted hydrogen, etc,, as before. c. s. Separation of Thorium from Cerite Earths. Wyrouboff and Verneuil. (Comptes r e d u s , vol. cxxvi., p. 340 ; through Rev. Chirn. Analyt. ajJpl., vol. vi. [7], pp. 112, 113.)-The method is based on the transformation of thoria into peroxide by means of hydrogen peroxide (proposed by Clive). The substance is dissolved in nitric acid, and a quantity of the solution corresponding to 0.5 gramnie (maximum) of the oxides is evaporated to dryness, and treated with 100 C.C.of water and an equal quantity of hydrogen peroxide, the whole being heated and stirred for several minutes. The bulky gelatinous precipitate is washed until the washings no longer give a precipitate with ammonia, and, after removal from the filter, is redissolved in a little hot water containing 2 grammes of ammonium iodide and 2 C.C. of concentrated hydrochloric acid, the hot solution being passed through the filter to dissolve any residual peroxide thereon. The hydroxide thrown down by ammonia is thrown on the same filter and calcined without washing, the filtrate being treated with ammonia to precipitate the other earths present in the substance. If the precipitate produced by hydrogen peroxide is not perfectly white, it contains cerium, and should be purified by re-solution in nitric acid and treating as before-a course advisable in any case, to ensure at the same time the total precipi- tation of the thorium present.c. s. Differentiation of Alkali Bicarbonates and Carbonates in Mixtures. A. Leys. (Ann. Chim. Aizalyt., vol. iii. [a], pp. 44-46.)-The precipitation of neutral alkali carbonates by magnesium salts being masked by the solvent action of an alkali bicarbonate or of borax in mixtures, the author has studied the reaction of the calcium salts in this connection, and finds that by using a saturated solution of calcium sulphate the neutral carbonates are thrown down immediately as an opaque white precipitate, whilst precipitation of the bicarbonates occurs only after prolonged contact with this precipitate.The crystalline powder, which then separates out, is readily distinguishable from the former. Thus, in the case of ‘‘ pure ” commercial sodium bicarbonate, if a quantity of water insufficient for complete solution be added, and a portion of the solution dropped into the reagent, an opaque precipitate indicating neutral carbonate is obtained. c. s. Separation and Estimation of Iodine, Bromine, and Chlorine. A. Carnot. (Comptes re?zdus, vol. cxxvi. [ 3 ] , p. 187 ; through Rev. Chinz. Analyt. appl., vol. vi. [3], pp. 34-36.) Iodine. -The neutral solution of chlorides, bromides, and iodides is diluted to 200 C.C. and placed in a stoppered 400 C.C. flask, terminating below in a narrow tapped tube.Here the iodine is liberated by means of 10 drops of sulphuric acid saturated with nitrous fumes, and extracted by shaking the liquid up with 10 to 15 C.C. of carbon disulphide, which, on settling, is drawn off through the tap.TEE ANALYST. 165 This operation is repeated twice, and on the last occasion the solvent should remain colorless. The carbon disulphide is placed on a moistened filter and the first washings are returned to the original liquid, the disulphide being then run through the perforated filter into a flask, where it is mixed with 30 C.C. of a fr per cent. solution of sodium bicarbonate and titrated with standard sodium thiosulphate. Bromine.--Several C.C. of 10 per cent. chromic acid and 3 to 4 C.C. of sulphuric acid diluted with its own volume of water are added to the liquid separated from the iodine, and the closed flask is placed in a boiling-water bath for an hour.The bromine is then extracted from the cooled liquid by carbon disulphide as in the case of the iodine, the disulphide solution being well shaken up with a little potassium iodide and 30 C.C. of 8 per cent. sodium bicarbonate, and the liberated iodine titrated with sodium thio- sulphate; the bromine is found by multiplying the weight of iodine by 0.6308. ChZorine.-The residual acid solution is diluted to 500 c.c., and warmed gently along with silver nitrate to came the precipitate to collect. The latter is purified from the silver chromate usually present by treatment with hot water slightly acidified with nitric acid, and is finally washed, dried, and weighed.c. s. Determination of the Strength of Hydrofluoric Acid Solutions. J. Zellner. (Monatsl~eft. fiir Clzenzie, xviii., 749.)-A volumetric process is recommended, con- sisting of titration by potash, using phenolphthalein as the indicator. A moderate excess of alkali is added, the solution boiled for a short time, and titrated back while hot. Comparative tests made volumetrically, in this way, and afterwards in the Bame portion gravimetrically, gave the following results, in parts per cent. : I. 11. 111. IV. By volumetric method ... ... 5.22 7.63 21.27 31-40 By gravimetric method ... ... 5-20 7.68 21-56 31.65 If the titration is carried out in the cold, the results, though agreeing between themselves, are about 1 per cent.below the gravimetric tests. For weighing the quantity of hydrofluoric acid taken for the determination, a cylindrical vessel of hard indiarubber is used, having an outlet at the bottom through a flexible small bore caoutchouc tube provided with a pinchcock. The apparatus, which weighs about 60 grammes, can be secured to the pan of the balance by a piece of platinum wire. It is first weighed full, and then after running out the required quantity of acid, the weight taken being obtained by difference. H. H. B. S. The Determination of Boric Acid as Potassium Borofluoride. I(. Thaddbeff. (Zeit. anal. Chenz., 1897, xxxvi., 568-637.)-After giving a summary of the various methods employed for the determination of boric acid, and showing the unreliability of any of those based on an estimation by difference, the author describes a modifica- tion of the Berzelius-Stromeyer method which he considers highly satisfactory when carried out exactly as described below.When in combination with a base, except potassium, the boric acid is distilled over with sulphuric acid and methyl alcohol, as in Rosenbladt’s apparatus, a regulated air-current being at the same time introduced into the distilling flask. The distillate from the substance containing166 THE ANALYST. 1 gramme or less of boric acid is received in a platinum basin containing a 10 per cent. solution of pure caustic potash, and when four successive quantities of 10 C.C. of methyl alcohol have been distilled over, is concentrated to half its volume on the water-bath. An excess of pure hydrofluoric acid is then added, and the evaporation continued until only a faint smell of hydrofluoric acid is perceptible.When cool, 50 C.C. of a solution of potassium acetate (specific gravity 1-14) are added, and the basin is allowed to stand for one or two hours at the ordinary temperature, the mass being frequently stirred with a platinum rod so as to ensure the whole of the potas- sium hydrogen fluoride dissolving. 100 C.C. of alcohol (specific gravity 0.805) are next added, the liquid carefully stirred and allowed to remain over-night. Meanwhile, a filter-paper has been prepared (a No. 590 Schleicher and Schiill, 9 c.m. in diameter), moistened with alcohol, dried at 100” to 110” C., and weighed in a stoppered weighing-flask. The insoluble residue of potassium borofluoride is washed on to this filter with alcohol of 0.805 specific gravity, and the washing con- tinued until on evaporating a few drops of the filtrate on platinum foil, no more residue remains than the small amount of borofluoride soluble in the alcohol (0.000014 gramme per c.c.). From 62 to 72 C.C.of alcohol are usually required. The filter and precipitate are then dried at 100” to 110” C. for three hours, and weighed. The following are some of the results obtained in this way with borax : Difference Borax taken. KBFI,. B20:< formed. from theory. Grammes. Grammeu. Grammes. Per cent. Per cent. 0.5 0-6631 0.1831 36.62 + 0.03 0.1 0.1308 0.0361 36-12 -0.47 1 1.3229 0.3653 36.53 -0.06 C. A. M. The Commercial Analysis of Bauxite. W; B. Phillips and D.Hancock. (Jour. dmey. Chenz. SOC., 1898, xx., 209-225.)-The author states that the formula given by Roscoe for bauxite, (AlFe),O(OH),, does not apply to the American mineral, which consists essentially of a mixture of aluminium trihydrate with clay and another aluminium compound, possibly a lower hydrate, I n assaying the material for alum manufacture it is usual to evaporate it with sulphuric acid until the latter begins to fume ; but in this way aluminium compounds are brought into solution which are not very suitable for the manufacture, and are certainly of very much less value than the readily soluble trihydrate. The author therefore recommends that the alumina soluble during one hour in sulphuric acid of a specific gravity of 1.516, at 100” C.shall be described as “free alumina,” and that soluble on evaporating the acid to fumes as (‘available alumina,” whilst the difference between the two shall be known as (‘ combined alumina.” He describes experiments which prove that practically the whole of the aluminium trihydrate is dissolved by the first treatment, and that concordant results can be obtained. The analytical method recommended is as follows: The sample is finely powdered and passed through a sieve of 100 meshes to the inch. Moistz~re.--Two grammes are dried to constant weight at 100” C. Available BZmzina.-Two grainmes of the bauxite are mixed with 10 C.C. of coldTHE ANALYST. 167 sulphuric acid (S.G. 1.516), and the basin gradually heated until fumes begin to appear. I t is then covered with a glass, and the heating continued for ten minutes.When cool, 100 C.C. of hot water are added, and after being boiled for five minutes the liquid is filtered, the residue washed, and the filtrate and washings made up to 200 C.C. Fifty C.C. are diluted to 300 c.c., 2 C.C. of hydrochloric acid added, the liquid boiled, ammonia added in slight excess, and the boiling continued for five minutes. The precipitate is filtered off, washed, dried, ignited, and weighed as alumina, ferric oxide, and titanium dioxide, and the two latter are separately determined and deducted. Estimation of Titawium Dioxide.-To 50 C.C. of the main solution, ammonia is added until there is a slight precipitate. This is just dissolved in sulphuric acid, and the liquid is made up to 350 to 400 C.C.and boiled for an hour. Any iron present is reduced by means of sulphur dioxide, care being taken that the liquid smells of the gas during the boiling. In this way the titanium dioxide is precipitated practically free from iron. The precipitate is filtered while hot through a double filter, washed with hot water, dried, ignited, and weighed. Estimation of Ferric Oxide.-This is determined in the filtrate from the titanium dioxide by reduction with zinc and titration with permanganate. Estimation of ( ( Free Alumina."-Two grltmmes of bauxite are mixed with 10 C.C. of sulphuric acid (S.G. 1.516) in a 4-oz. Erlenmeyer flask, which is provided with a perforated stopper. The flask is heated on the water-bath at 95" to 100" C, with frequent shaking for an hour, after which 100 C.C.of hot water are added and the flask kept in the water for ten minutes. The liquid is filtered, the residue washed with hot water, and the alumina determined in the filtrate as before, with the exception that the titanium dioxide, which is not dissohd under these conditions, is not determined. The precipitate consists of alumina and ferric oxide, and the latter is separately determined in the usual way and deducted. Combined Alumina is the difference between the available alumina and the free alumina. I n order to determine the silica and the total alumina, etc., the insoluble residue left on treating the mineral with the sulphuric acid may be ignited with the filter- paper, the ash fused with potassium bisulphate, and the melt left in cold water containing at least 5 per cent. of sulphuric acid until decomposed.The silica is filtered off, ignited, and weighed, and the alumina, ferric oxide, and titanium dioxide determined in the filtrate, and added to the amounts found in the determination of the available alumina. I t is not advisable to determine the silica in the insoluble residue by treatment with hydrofluoric acid, since some of the titanium dioxide is simultaneously volatilized. NOTE.--It is well known that if sulphuric acid, as well as hydrofluoric, is C. A. M. employed in the elimination, the titanium dioxide is completely retained.-B. B. Analysis of Calcium Carbide. H. Bamberger. (Zeit. aizgezo, Clzenz., 1898, 196-198.)-In place of the ordinary methods of determining volumetrically the amount of acetylene obtainable from a given weight of carbide, which have the draw-168 THE ANALYST. back that a correction must be made for the gas absorbed by the liquids with which it comes in contact, as well as the ordinary corrections for temperature and pressure, the author prefers to use a gravimetric method; the principle of which is the same as that for the determination of carbonic acid in carbonates by difference, C. A. M. On the Products of the Decomposition of Calcium Carbide by Water. E. Chuard. (BzdZ. SOC. Chim., 1897, xvii., 678, 679.)-The author has established the presence of ammonia not only in the acetylene liberated from the carbide, but also in the residue. For 100 parts of calcium carbide the gas contains from 0.03 to 0.06 of ammonia, the residue 0.24 to 0.40. The animonia liberated with the acetylene is derived from the decomposition of calcium nitride, Ca,N, -t. 3H,O = 3Ca0 + 2NH,, whilst that in the residue is a product of the decomposition of calcium cyanate :- Ca(CNO), + 3H,O = CaCO, + CO, + 2NH,. Other impurities invariably present are phosphoretted and sulphuretted hydrogen. It is to the presence of the former, the amount of which is usually 0.018 to 0-032 per cent. on the carbide, that the insecticidal properties of crude acetylene are probably due. C. A. M.

ISSN:0003-2654    

DOI:10.1039/AN8982300163

出版商:RSC    

年代:1898

数据来源: RSC

摘要:

168 THE ANALYST. LEGAL. QUEEN’S BENCH DIVISION. COURT FOR THE CONSIDERATION O F CROWN CASES RESEIGVED. Reprinted from the “ Times ” of iMuy 2, 1898. (Before the LORD C H I E F JUSTICE OF ENGLAND, MR. JUSTICE DAY, MR. JUSTICE Wrms, MR. JUSTICE GRANTHAM, MR. JUSTJCE WRIGHT, MR. JUSTICE KENNEDY and MR. JUSTICE CHANN ELL). PETCHLEY 2). TAYLOR. THJS was a case stated by a Metropolitan police magistrate upon convicting the appellant upon an information preferred under.the Sale of Food and Drugs Act, 1875, for unlawfully selling to the prejudice of the purchaser milk which had 97 per cent. of the original fat abstracted, so as to affect injuriously its quality and substance, without making disclosure of the said alteration, contrary to Section 9 of the above Act. Mr. George Elliott appeared for the appellant; and Mr.Courthope Munroe for the respondent. On November 13, 1897, the appellant sold to the respondent a tin containing a substance described as ‘( Cup Brand Condensed Milk.” On the tin were the words, ‘‘ This tin contains skimmed milk with nothing added but the finest sugar.” The substance in the tin was proved to be separated milk, or milk from which the cream had been separated by means of a machine Galled a separator, and that 97 per cent. of the original fat had been abstracted. It was also proved that the term ‘‘ skimmed milk” meant milk from which a portion of the f a t had been removed by the process of skimming the surface of the milk, and that the greatest amount of fat that could be thus removed was 63 per cent. Mr. Elliott contended that the alteration was sufficiently disclosed by the term ‘‘ skimmed milk,” and cited ‘‘ Jones v. Davies ” (69 L.T., 497) and “ Platt v. Tyler” (58 J.P., 72). The Court yesterday dismissed the appeal. .

ISSN:0003-2654    

DOI:10.1039/AN8982300168

出版商:RSC    

年代:1898

数据来源: RSC