752 CHOLERA AND ITS PROGRESS.

enclosed in a bulb immersed in it to rise in a tube and checkthe supply of gas. The principle is similar to that of Page’sregulator. The pressure of the gas is rendered constant bymeans of the regulator (c).

METHODS OF STAINING BACTERIA.In order to stain bacteria from a cultivation, or when

they "are present in a liquid, a small portion of the culti-vating material or of the liquid, containing them is

placeu on a thin cover-slip, another cover-slip is placedover this, and the two are firmly pressed together.The two slips are then slid one from the other, andeach with a very thin layer on it is set aside to dry. Inpreparing to stain, the cover-shp is first heated, either bybeing pissed three times rather slowly through the flame ofa spirit lamp or else by being gently baked for an hour at atemperature of about 1100 C (100°-120°) This may be doneconveniently by arranging a plate of copper on a stand andheating one end of it with a i-pirit lamp. When the tem-perature of the plate has become coostant at the differentparts, the boiling-point is found by drawing a wet glass rodover it and noticing where the water boils. Just beyondthis is the region of the required temperature, and the cover-slips are arranged here.The aniline dyes, methyl violet, methylene blue, fuchsin,

gentian violet, vesuvin, and Blsmarck brown are commonlyemployed for staining. About 5 to 10 per cent. of a concen-trated alcoholic solution of one of these is added to waterand the mixture is filtered. The cover-slip which has beenheated i3 floated on this solution with the film downwardsuntil it is stained, after which it is washed in distilled water,dried, and mounted in Canada b’sm. In order to obain afiner preparation, the cover-slip may be left longer in thestaining solution and then immersed in a dilute solution( to 1 per cent.) of acetic acid. This removes some of thecolour. It is then washed and mounted as before. Analkaline solution of methylene blue is better for the bacteriaassociated with glanders, typhoid fever, and some others.This is prepared by adding thirty parts of a saturatedsolution of the dye to one hundred parts of a dilufe solutionof caustic potash (1 in 10,000).

Tubercle bacilli may be demonstr,tted in sputa in thefollowing way :-Some of the thicker parts of the sputum

is placed on a cover-slip and dried and heated in the mannerabove described. After it has been so treated it is stained ina solution of fuchsin or gentian violet prepared by theWeigert-Ehrlich method. To prepare such a solution wateris shaken up with aniline oil until it is saturated with it; Iit takes up about 3 per cent. The undissolved oil is re-moved by filtering the mixture through muist filter-paper.Eleven parts of the saturated alcoholic solution of fuchsm orgentian violet are added to 100 of this watery solution ofaniline, and after the mixture has been filtered the cover-slips are floated in it. At the ordinary temperature the filmis allowed to stain for twenty-four hour?, at the body tem-perature for two hours, and for a temperature near theboiling-point of water a few minutes are i-uHicient. Af erthis the cover-slip is washed in distilled water. The wholeof the film-mucus, pus cells, tubercle bacilli, and otherbacteria-are now all stained red or violet, a" the case maybe. The next step is to dip the cover-slip for a moment intoa strong solution of nitric acid, prepared by adding one partof fuming nitric acid to two of water, and from this they areimmediately returned to distilled water. The slip is thenfloated in a watery solution of some other dye, one beingchosen which will contrast strongly with that first used.Thus, if fuchsin was employed in the first staining, the cover-slip may now be placed in methylene blue, or if gentianviolet was the first, vesuvin may be used. The films arestained for half an hour or longer, according to the

strength of the solution, and are then washed, dried, andmounted in Canada balsam. The result of this process isthat the tubercle bacilli remain staimd by the first dye used,while all the res of the film has been so acted on by thenitric acid that the first dye is replaced by the second, andthus the tubercle bacilli stand out red on a blue ground, orviolet on a brown ground, as the case may be.A tissue which contains bacteria should be hardened in

absolute alcohol or methylated sp;rit; in the former case forone or two days, in the latter for two or three weeks. Whensections are cut it is best to freeze the tissue. It is firstsoaked in water until the alcohol is removed-i.e., until itsinks, in all cases except lung specimens-and then in stronggum. The solution of gum may conveniently be kept sweet

by adding a little salicylic acid to it. When an ice and saltfreezing machine is used, the pure solution of gum sets to toobrittle a mass to be cut without injuring the sections; inorder to prevent this five or ten minims of methylated spiritmay be added, or a mixture of two parts of gum and one ofsyrup may be used. In an ether freezing machine therequired consistence of the mass may be obtained bymoderating the supply of spray. The sections are floatedin water to dissolve the gum. The best stain for mostbacteria in tissues is the alkaline solution of methylene blueabove described. After being stained from one to two hoursthey are washed in dilute acetic acid, then successively indistilled water, absolute alcohol, and oil of cedar, andmounted in Canada balsam. The oil of cedar takes outthe colour less than oil of cloves. The watery solutions offuchsin, methyl violet, and gentian violet may also be used.In order to stain the bacteria one colour and the tissue

another, the sections may be placed first in methyl violet,or gentian violet, and then in picrocarmine ; but thismethod requires considerable practice. Gram’s method isfor the same purpose, and in many cases gives good results.The sections are transfered from water to absolute alcohol,and thence to a Weigert-Ehrlich solution of gentianviolet, for from one to three minutes. In some cases it isbetter to place the sections in absolute alcohol betweenthis and the next stage. They are then placed in a solutioncomposed of one gramme of iodine, two grammes of iodideof potassium, and 300 cubic centimetres of water, wherethey remain for three minutes or more, and are then passedon to absolute alcohol, oil of cloves, and Canada balsam. Thebacteria are stained violet and the tissue pale yellow. Inorder to deepen the colour of the tissue the section may beimmersed for a moment in vesuvin solution after the alcoholbath succeeding the iodine solution. It is then placed inalcohol and oil of cloves, and mounted in Canada balsam.Sections of tubercular tissue may be treated by the nitricacid method in the same way as the cover-slips. After thesecond stain they are passed through absolute alcohol andoil of cloves, and mounted in Canada balsam.

In staining sections for photography, a saturated waterysolution of vesuvin is used, the brown colour coming outdark on the plate.

CHOLERA AND ITS PROGRESS.

FOR the past fortnight there has been a further diminutionof the cholera mortality in Naples, but it has been by nomeans a steady one, the deaths having varied from thirteento seventy a day, and it is to be feared that some time mustyet elapse before the disease will have ceased to exist in thecity. Up to the 20th inst. the deaths that had been admittedby the official records exceeded 6500 in the city, in additionto over 700 in the province of Naples. The other provincesto which the disease clings with most tenacity are those ofGenoa, Cuneo, Bergamo, and Crernona; but with the excep.tion of Genoa, from which information does not come veryrrgularly, the mortality is a diminishing one, and there aregrounds for hoping that, even so far as the town of Genoa isconcerned, a very material abatement in the virulence of,theoutbreak has taken place.From France the news is more cheering than it has

hithtrto been since the commencement of the epidemic.On1y very occasional deaths are now occuning in eitherToulon or Marseilles, and although a somewhat persistentprevalence of cholera was maintained in the Department ofthe Pyrénées Orientales duriog the earlier half of the presentmonth, yet an absence of news as to fresh deaths in thatportion of France may, it is to be hoped, be taken as anindication that the outbreak has practically subsided.Much the same may be said as regards the Spanish out.

break. Up to about October 10th a daily return of choleradeaths was made as regards the province of Alicante, wherethe disease first appeared, and where the mortality waslargest; but now, although no authoritative announcementhas been made as to the cessation of the epidemic, theabsence of news gives some hope that this result may, atleast, be near at band.As regards the future, there is some hope that the terrible

visitation of 1881 will not be thrown away. From Naplescomes news that early steps are to be taken to secure theproper sewerage of the ciry, and to enforce the closure of the

753REPORTS OF MEDICAL OFFICERS OF HEALTH

many wells which are resorted to, and which must obviouslyfrom their surroundings be subjected to constant pollution.But much more than this is needed in Ndples, and it is

perhaps in part owing to the gigantic scale on which sani-tary reform is needed that so little improvement followed onthe previous epidemics which devastated the city. Theovercrowding of houses in area and of people in dwellingsis such that purity and wholesomeness of air cannot possiblybe secured, and, together with a reconstruction of much ofthe town, there must proceed the erection of buildings totake in those who will be ejected from the old tenements.Whether Naples can undertake this large task except withthe aid of the national purse has to be seen. But untilit is undertaken the city will remain a source of danger tothe Peninsula.

Public Health and Poor Law.LOCAL GOVERNMENT DEPARTMENT.

REPORTS OF MEDICAL OFFICERS OF HEALTH. (

E

Hampstead. -The parish of St. John, Hampstead, not onlycontinues to enjoy a small death-rate, but after makingallowances for the deaths of non-parishioners in public in- stitutions, the rate for 1883 is reported by Dr. Gwynn asbeing the lowest on record-namely, 11’26 per thousand.The zymotic death-rate was also low. As regards the in- flllenee of the North-western Hospital of the Asylums Boardin the district, Dr. Gwynn states that there has been no l

special incidence of scarlet fever in its vicinity. He attri- fbutes this in a very great degree to the fact that a severe epidemic during the two previous years had used up thematerial necessary for its development ; but it must, at thesame time, be admitted that, quite apart from this condition, a careful administration has all along prevented any spreadof this disease in the neighbourhood of the London FeverHospital. Since the end of 1883 small-pox wards have alsobeen opened at Hampstead, but the number of patients is tobe limited to forty. The question of the efficient removalof house refuse bids fair before long to become a pressingone in Hampstead, as it has done elsewhere in the metropolisand in large centres of population, and it is anticipated thatthe difficulty will have to be met by the erection of adestructor. The provision of baths and washhonses is incontemplation, and improvements in the ventilation of thesewers are about to be undertaken.Islington.-In St. Mary’s, Islington, the death-rate was

17’1 and the birth-rate 32 8 per 1000 in 1883. Passing fromstatistics, Dr. Tidy gives some account of the epidemic ofenteric fever which prevailed mainly in St. Pancras lastyear, which was due to milk infection, and which spreadalso into the Islington district. An account follows as tothe other infectious diseases which prevailed, there is a shortsummary of the sanitary work of the year, an account of thequantity and quality of the water supplied to the district,and then follow the four quarterly reports issued during theypar as to proceedings taken under the Sale of Food andDrugs Act.Kensmgton.-During 1883 the death-rate for Kensington

was 15 per 1000, a lower rate than any known since vitalstatistics for the parish have been available. In dealingwith the prevalence of infectious diseases in the parish, Dr.Dudfield shows that considerable care is taken by his de-partment to prevent the spread of infection, employers beingcommunicated with in the case of persons having scarletfever in their houses, and other kindred precautions beiogtaken. Reference is made to an outbreak of enteric feverwhich occurred last autumn in the neighbourhood of Earl’sCourt-road. The prevalence appeared almost certainly tobe associated with a special milk service; but though everyfacility for an investigation was rendered, the actual sourceof the infection was not discovered. The existence of theFulham or Western District Hospital in the immediatevicinity of an important portion of the Kensington districtleads Dr. Dudfield to report in detail as to the operations ofthe Metropolitan Asylums Board, aud he next proceeds toconsider a localised outbreak of small-pox which occurredin the vicinity of that hospital during the course of the pastsummer. This outbreak led to a renewal of Mr. Power’sinvestigations as to the influence of the Fulham hospital,

but according to Dr. Dudfield the prevalence had commencedbefore any patients were admitted into the hospital. If thisbe so, the information to be derived from the inquiry willprobably be limited, but Mr. Power’s report must be waitedfor before any definite opinion on the subject can be ex-pressed. In the absence of any system for the compulsorynotifioation of infectious diseases, a plan has been arrangedby which Dr. Dudtield receives a large amount of voluntaryaid in this matter from registrars, relieving t’f&cers, the resi-dent medical officer of the Kensington Dispensary, the ChiefCommissioner of Police in so far as constables and theirfamilies are concerned, the postal authorities in connexionwith postmen and their families, school authorities,clergymen, district visitors, and many private medicalpractitioners. From one or other of these sources severalhundred cases of illness annually come under notice, andmuch useful work results ; but still the number ot concealedcases remains very large, and no voluntary system can beexpected to be thoroughly efficient. These and other pointsof general sanitary interest are fully discussed in Dr. Dud-field’s report, but at the same time he does not fail to supplya large amount of information as to the local circumstancesof his district, and also to indicate the directions in whichsanitary action has been taken. The Kensington reportsare, in short, amongst the most complete that are issued.

St. Giles.-Mr. Lovett reports a death-rate of 21.5 per1000 for the district of St. Giles and a birth-rate of 30’7; thezymotic rate was 2’20 per 1000, or somewhat below that forLondon generally. Reference is made to a heavy zymoticdeath-rate in the Peabody Buildings in Great Wild-street.Careful examination of the premises failed to discover anysanitary evil, and in view ot the fact that the majority ofthe deaths were due to diseases such as measles, the circum-stance, affecting as it did only a population of some 1500,must probably be regarded as exceptional, and as havingbut little bearing on the healthiness of the buildings. Con-siderable improvements have been effected in St. Giles’s, asregards dwelling accommodation, during recent years, andmore work of the same description is in contemplation. Inthe general report issued by the Board of Works for thisdistrict we note with regret that the erection of public re-tiring rooms for females has been opposed and deferred, andthat no present effort is to be made to meet this crying wantin a city which is so vast in area that the need for supplyingit is greater than anywhere else.

Wandsworth.-Taking the district as a whole, the birth-and death-rates were 35.1 and 17 8 per 1000 respectively, andthe rate of mortality from the so-called principal zymoticdiseases was lower than in any of the last seven year... Thegeneral sanitary work of the year is stated to have beengreater in amount and of more importance than that whichhas hitherto been accomplished. It included a detailed in-spection of dwellings, the removal of a large number ofnuisances, and measures to prevent the spread of infection.The scavenging of the district, however, remains very im-perfect, and considerale inconvenience and nuisance isheoce occasioned to householders. Following on the generalreport is a separate one by each of the five medical officersof health. In the report on the Putney and Roehamptondivision reference is made to a serious epidemic of diphtheriawhich caused twenty-four deaths. Unfortunately, however,the investigation which followed failed to show how thedisease had been brought about. In West Ba.ttersea com-plaints were made by the inhabitants as to the dirty andunwholesome state of the water; this was, on inquiry, foundto be due to the fact that the dead end of a water-pipe hadlong remained uncleaned, and when it was first opened thefluid which came forth was for several minutes of a mostfilthy description. This dead end has since been done awaywith, the circle being completed by joining the pipe on toanother one.

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VITAL STATISTICS.

HEALTH OF ENGLISH TOWNS.

During the week ending the 18th lest., 6060 births and3545 deaths were registered in twenty-tight of the largestEnglish towns. The annual rate of mortality in these towns,which had been 20’1 and 19’8 per 1000 in the two preced-ing weeks, rose last week to 21 1. During the past three weeksof the current quarter the death-rate in these towns averaged20’3 per 1000, against 20’7 and 19’4 in the correspondingperiods of 1882 and 1883. The lowest rates last week in these