THE FLY.

Gisborne Times, Volume XXVII, Issue 2652, 6 November 1909, Page 3 (Supplement)

THE FLY.

The “typhoid flv” has been found out at last. He is no longer the pretty, harmless creature to be rescued from the coffee, “shooed” off the bread, 01dug out of the omelet. He is the bearer of dysentery and typhoid fever, of cholera and tuberculosis, ophthalamia, and: even small-pox. In our last war lie killed more men in camp than the Spaniards killed in battle. Almost overnight AVe are beginning to realise Avhere the fly is born and bred, and where his travels take him, and what it is he washes off -incjthe milk. Certain facts are coming to light that are calculated t-o make the householder sit up and take notice —facts, moreover,, which anyone can verify for himself from what he sees Avitli his own eyes, ami Avhat he can find in almost anv set of reports of any Board of Health. —Tlie Deaths of Babies Measured by the Life of Flies.—

For example, according to the latest Massachusetts report, ime babies of Boston more than held tlieir own through th& summer of 1907, so far as ordinary infectious diseases are . concerned'. To the whole group of airborne maladies forty-five infants succumbed in June, and only twenty-six in August. On the other hand, from gastro-intestinal diseases, including the whole group of epidemic disorders commonly lumped together as cholera infatum, in which the contagion comes through infected food, the forty deaths of June avere doubled in July; became six times as many in August, Avhen xiie flies are apt to be most abundant- continued at five times the June level during September, Avlien the flies are stiu abundant in spite of the cool weather; and did not become normal again until No\ r ember! Hot weather! does one say ? In a large part, no doubt, for heat is good for microbes, and good for flies, ana bad for babies. But September is cooler than July, and has more flies — and shoAvs tivice as many deaths from the particular disease that flies disseminate. October is certainly cool, but its mortality is almost as great as that : of June and July .together. I Or take the same facts from a slight- | ly different standpoint. Breast-fed! babies are exposed to dangers -through j air and Avater, but not through thenfood, and they the, at the Avorst, a j third faster during fly-time. “Bottle" j babies die three and four times faster. —What One Typhoid Fly Can Do. — I But, after all, one does not need statistics like these to make him suspicious of the fly; nor even such pains- . taking studies as that of Daniel D. Jackson, in Neiv York City, who by ! means of flytraps set in various places shoAved a remarkable close coincidence betiveen tlie prevalence of flies and the onset of fatal cases of typhoid fever. The convincing evidence is that flies haA r e been caught AAdth the goods. It is an old device, almost -as old as | .the science of bacteriology, to let a tiy crawl about on a sterilised plate of Nutritive gelatin such as is commonly, employed for growing cultures of bac- j term. At first there is no sign; butafter a few hours in the incubator the insect’s track on the gelatin is outlined in flourishing colonies of microbes. Virtually every time the fly has put down any one of its six feet, he has planted at least one germ. A march of one inch -results in a hundred vigorous cultures. It is a pretty clean fly that does not bear a thousand germs. A fairly dirty one will carry fifty thousand. A fly fust back from the swill-pail or pig-pen, at the height of the season for flies and germs, carries a load approaching the record number in a drop of city milk ■ and this is well, into the millions. .To be sure, in ninety-nine, cases out of a hundred, these bacteria are pretty liarmless. A few million bacilli of sour milk more or less, or even of common bacteria of putrefaction, make no special difference one Avay or the other But there is always the hundredth case. A whole group of dreadful diseases, among them typhoid fever and the infectious intestinal disorders that slaughter the little babies through one summer, are propagated only as the faeces of a sick person somehoAV or ether mingle Avith the food of a; well one. What is there that tlie housefly likes better than to-Avalloiv and feed in this! Then he repairs to store or 'kitchen and craivls over our food. It is easy to see why we, who, during the Spanish war let the camp flies go about as they liked, lost four men by disease for every on© by wounds; while the Japanese, aa-lio made war on the flies in camp as efficiently as upon the enemy in the field, lost four men by ivounds for one by disease. Perhaps W was just as well for us that we weror fighting Spain and not Japan. A Perfect Contrivance for Spreading Fatal Diseases. — __ The fact is that, regarded as a contrivance for disseminating the germs of fatal diseases, the fly is one or. .Nature's masterpieces. A fairly large bacterium is as much smaller than a flv as a fly is smaller than an elephant. The microbes of many of our ordinary catagious disorders are a thousand times more minute than this. The insect, moreover, is equipped with spines, hairs, .folds, cavities, and projections innumerable lor microbes to Sr to. In addition, each of its six feet has a sticky pad which we used to. call a sucker, adhesive enough to hold the fly on a window pane, and there loro just the thing for picking up the germs by the hundred ° ne credit reports of a single fly, filthy n™ l a swill-barrel, loaded with. 082,000 bacteria of one species alone Moreover, the fly, living on infected food, takes the microbes into his own digestiv tract, carries them about for days, and denosits them iby thousands m the /‘fly-specks.” * There, for e ? am gJ®> Bacillus tuberculosis may live for two be bad enough if the fly merelv crawled about in the sputum of a tuberculosis patient or the dejacta of a case of typhoid, and then amp y infected the food on the way te om anouths. It does worse than this, it starts a culture of the deadly gemns in the food Avhich we are to eat to-mor low; and by the time to-morroAV arrives the single microbe has become a thous and. „ —Six Million and a-Half Germs to a Fly.—

Here is a sample of a class of facts w hick may well give paterfamilias •jEe. At one of the Connecticut agricultural experiment stations, by way of finding out bow many bacteria a fly can transfer into a. .milk-jar, shaking up flies in sterilised water and estimating the numbers off. The record number was 118,800,001) irom eighteen individuals, cr more than b,500,000 apiece. ■ T , These, to be sure, happened to be, for the most part, harmless. But, suppose they had not happened to be harm-

THE DISEASE OF THE HOUSE.

(By E. T. BREWSTER, in “ M’Glure’s Magazine.”)

less! Recent experiments of the Massachusetts State Board of Health have shoivri that, at ordinary room temper- ' atures, Bacillus typhosus at least doubles its numbers every three and ono-half hours. Bacillus dysenteriae multiplies somewhat more slowly, and Bacillus diphtherioe half as fast. Cold, short of freezing, does not affect any of the three. One typhoid bacillus, therefore, in fouriy-eignt hours, becomes 16,000, Avhile the culture of typhoid germs introduced into milk not infrequently crowd's out the harmless sorts and becomes the dominant species. But microbes flourish and multiply in all sorts of human- foods, and the human body, Avhich might have resisted tlie attack of a small number, quickly succumbs when the enemy attacks in force. At Dartmouth College they hav e lately tried testing the air of their I class-rooms by letting the dust settle on gelatin plates. If more than forty bacteria settle in ten minutes, the room is disinfected. This method does not pretend to eliminate the pathogenic .organisms; it merely keeps down their numbers. But the effect has been notably to diminish sickness among the students, especially mild affections' niie tonsilitis, measles, and ordinary colds. It now- appears that so simple a matter as filling a child’s teeth cuts doAvn tivothirds of the chances of its taking the common infectious diseases of childhood, for no other reason than that the cavities in'the teeth no longer serve as breeding-places for the germs already in the mouth. The Avorst of the typhoid fly is not merely that he visits the sick neighbor and brings home a feAV thousand uacilli; he concentrates the cantagion in a culture of the disease. The sucking flies are bad enough, with their sticky, germ-laden feet and tlieir proboscides thrust into everything moist. Still, they do give tlieir victims some sort of a chance, for tlie germs they bear liaA 7 e to run their chances with human digestive fluids. The biting flies are even worse, for they innoculate directly their victim’s blood. —A Greater Peril Than the Automobile. —

Doubtless, in the course of time, the police, or Congress will do something. But in the meantime Avliat is the careful housekeeper to do? Given one easygoing neighbor, and by midsummer the flies will swarm by the ten thousand; and any one of them, loaded with tlie right kind of bacteria, puts the children o» The Household in greater peiil than all the automobiles that pass the street in a year. There are housekeepers who rely on the screens and flypaper. There are kitchens where most of the accidental deaths among the insect population occur because the flies push one another off the ceiling into the food. "Neither method is adequate under modern conditions.The fact is, the typhoid, fly has opened up a neAV branch of. medicine. Ihe healing art began with. the. diseases of mankind. - After hundreds .of years, came the veterinarians and the study of the diseses of animal's. _ 1 Lately av© have bogun. to treat the diseases of plants. The next step must be extended m scientific medicine to the diseases of houses. And all disease of houses that is the worst lias for its microbe the unfortunately when its comes to treating diseases of her dwellng, the best of housekeepers is in the herb-tea and the mustard-poultice stage of medicine. All she knows about, the, fly is that h© Avants to get into the house, and that she Avants to keep him out.. Why he Avants to get in, and how he happens to be there at all, are questions belonging to a stage of preventive household medicine which we have still to reach. . •, , • Nevertheless, science has some contribution to make. There are certain facts concerning the household ny which, when the housekeeper understands them, will help not a little m the conduct of the war.

Why Elies Gather on .the Screen Door. — *_ It is a long step towards keeping flies out of the house when one understands why they want to come in. Common opinion has it that the fly meditates profoundly on the conduct or hte, knows what he wants and why he wants it and deliberately joins the assembly around the top of the kitchen screen door to Avait for the chance to dodge in when the cook comes out. As a matter of fact the fly is no such rational thinker. He has one supreme mdfive in' life', and that is—to inove towards the strongest smell. He enters -me house because there are more smells inside than out, and, once in, he frequents the kitchen because there are more smells there than in the parlor. The fly does not find its food by sight, but by odour. only. In fact, the fly s sight is extrerriely poor; for Nature has never solved the optical problem of making a small eye see as clearly as a large one. The customary swarm of flies around a kitchen door means only that the kitchen windows are opened at the bottom, and since the top of the door is the highest opening in the.room, that, rather than one of the Avindows, is carrying the ontdraft and the smell of yesterday’s soup. The moral is, adjust the ventilation so that the outdraft shall be through the screened AvindoAV. No fly will) ever see a door open and deliberately fly in. For the same reason, all unused: chimneys connected Avith fireplaces ought to be screened just as carefully as the AvindoAVS. In the cool weather of early fall, when the flies are Worst, the chimney draft is usually outward. The fly never hunts for an opening to come in by; but he does head upstream to an air current which. bears the savour of most human foods. Therefore Avhen the air of a home goes out of a chimney, the flies come in.

—Baiting the Fly With an Odour. — This is where the vegetarians have the advantage over the rest of us. The smell of “triscut” and “corn-flakes" and “strenathfude” does not carry lik© the smell of meat. One only has to compare the conditions in a vegetarian restaurant, with those of the common sort, to realise that the difference in the appeal two make to one’s own nose is a;fair measure of the attraction of the 'different sorts of food for the fly. Here, also, is one advantage of a good cook who can keep 'food flavors in the food instead of • spreading them-, over the landscape. There is a good deal that might be said in favor of a fly less diet for summer. The fly’s main purpose in life, then, is! to follow up smells. Here, therefore, is his weak side, and here the housekeeper. must attack him. If the fly goes to where the smell is, there is the place to put the fly-paper.. , A better way still, ’ sometimes, is to bait the “tanglefoot:’’ Any strong-smelling food will answer; cheese, meat (which need

not be strictly fresh), Avhatever flies collect on, can be used to lure, them to destruction. Of tivo sheets of fly-paper similarity placed', but one baited and the other not, the baited paper will catch tAVo or three times as many flies as the other. But the bait must be, for the fly, the most prominent odour in the room. So there are kitchens' where this deA 7 ice is foredoomed to conspicuous failure. At the same time, hoAvever, tli«.t one is making his appeal to the fly’s nose, one must not forget another important set of„ impulses—the fly’s reactions to light. Nearly all adult insects are, in greater or less degree, subject to that strange attraction Avhich drUAVS the pro-v-erbial moth to the candle flame. All, in our scientific; jargon, are “positively phototropic to lights of moderate intensity.” This does not mean in the least that they prefer light to darkness, or that they have either interest or f curiosity concerning candle-flames. They simplv act like a green plant in a windoAV, and head upstream to tlie lightray. The green plants Avhich move move lightAvard. So, for the same reason, does the insect. Curiously enough, too, just as in the case of the plant, it is the blue component, of the light that is. most effective. .Too bright a light, hoAveA r er, works the other way. The insect becomes “negatively phototropic,” heads away from the light, and if it flies at all, flies, on the Avhole. toAvards the darker regions. In general, too, each sort of insect has its special place Avhere' it draAVS the line between the moderate, light toivard Avhich it turns its head, and the excessive light on Avhich it turns its back. With most insects, also, the point at which occurs the change from positive phototropism to negative depends 011 temperature food-supply, and verious other changeable conditions. Those terriblv scientific people, the Germans, are utilising this common phototropism of insects to slay objectionable moths by the ton. They set a light, of just the right size and brightness, Avhere it will attract the moths into the sphere of influence of a vacuum fan. ' Aftei* that nothing remains to be said concerning the moths. —A Scientific Device for Ridding the House of Flies.—

The common fly is much less sensitive to light than the moth; nevertheless, he is sufficiently pliototropio to be vulnerable on that side. Every housekeeper has noticed that on certain cloudy days her flies collect on the screens and Avindoiv panes, as if they were trying to get out. It is a good plan te let them. Tlie dim illumination inside the lxouso has made them uncommonly sensitive to light, while outside the light is not so bright -that their phototropism becomes negative. In fact, one can usually, after a little experience, no matter what the weather, clear a room of fliesl by the obvious device of opening the wiudoAV and letting them flv out. The light in the room must be dim, but not so dim as te remove the stimulus to movement. There should be a single bright opening, so that all light sluul come from one region. That single opening should usually bo where there is shade outside, that the light there may not be too bright. These conditions fulfilled, the flies can no more stay in the room than a house-plant can grow awayfrom the window.

Or, if one fears to leave a window unscreened in fly-time—this certainly does take ..nerve . or an uncommon faith in science—it is a good plan to adjust tlie light to bring the flies towards tlie Aviudow, and equip the bright part of the room with fly-paper. This device, combined with the odoriferous bait on the paper in the bright area, is often most effective. The tendency to head towards a smell is also of the nature of a tropism. With the two tropisms working together, the problem of free Avill for the fly becomes purely academic. There is really a great field for inventions which shall utilise the tropism of too abundant insects. It Ai'ould be well Avbrth while for the possessor of a room infested with carpet-moths to experiment Avith an electric light of one or tAvo candle-power set overnight in the miduie of a sheet of “tanglefoot.” So far as I know, only one such inA'ention lias been aimed at specifically at the house-fly. This is a contrivance invented by the late EdAvard Atkinson, of Aladdin oven fame—“ Shin-bone Atkinson,” he used to be called by persons Avbo resented bis attempts “to ameliorate the condition of the eating classes.” —Sending the Flies Doavu a “FlyEscape.” Atkinson’s “fly-escape” is a Avindow, preferably on tlie east side of the kitchen, Avhich has in .its lower half a single large pane set flush Avith the sash on tne side towards the room. Thus the loAver part of the windoAv, sash and glass together, is a single unbroken surface, on which a fly can crawl unobstructed. The Aisual position of the sashes, moreover, is re-versed, so that the upper sash drops inside the lower. , . ' , The trap is set by dropping the upper sasli six or eight inches and draAvmg the curtain to itsdower edge. The positively phototrophic flies in the dim light of the early- morning are obliged to go to the windmv. But flies are also to a marked degree negatively geotrophic, that is to tsay on a vertical surface head up. When they craAvl therefore, they craAvl upAvards. CraAvling upwards, they crawl between the two sashes and out of doors, where they belong. The inventor of the “fly-escape” has unlimited faith in it; but the general run of cooks do not seem to be well grounded in animal psychology.' There, is, theoretically, a still simpler form of “fly-escape”—-though, unfortunately, it can only be used under special conditions. The fly’s eyesight is extraordinarily bad, so bad that if he looks at an ordinary screen against a dull background he sees it as a continuous surface; but if he looks at the screen against a light he does not see it at ail. This is even true of a screen Avith a half-inch mesh. If, then, a room Avith windows on one side only were screened with coarse netting, the flies Avould go out freely toAvards the light, but come in only as they blundered through. A fine screen does noticeably _ check the draught through a Avindow, and one can easily imagine circumstances under which one Avould bo willing to put up with a few insects for the sake of much fresh air. Incidentally one may note that there is no use in trying to slap one’s palm down on a fly, because he willsee it coming «and stand from under. The hand of vengeance should approach slowly, and then, as the victim is about to take flight, Avhile tlie hand remains motionless, the middle finger should bo quietly dropped on his back. The fly, Avith his little eye, can see the .movement of the hand against the background of the room. He cannot see one finger against the background of the rest. The first move, then in the campaign against the typhoid fly is ,to find out why lie comes into the house at all; the second is to replace l these motives for coming in by motives equally strong for going out. There remains, however,

still another matter, before Ave call in the police: the reason Avhy the typhoid, fly conies into, the Avorld at all. —Flies Ahvays the Stigma of Untidiness.—

Fundamentally, the fly is in the world because there are moist and smelly things there. Flies cannot breed in dry places; they will not breed in clean ones. In general, then, whatever is.damp and dirty contributes to the plague, Among other contributory negligences are stables ; cow-byres; piggeries; decaying vegetables, meat and cheese ; dead lanimals; rotting straAV, paper, and rags; old mattresses the thousand _ and one decay-able objects . that get into the ash-barrel, and tlie dump, Avhen they ought to go into the fire. It we had no decaying organic matter, we should have no flies. For every living creature tends to multiply up to the Emit of its food supply. Communities that feed tramps at every back door have tramps, and communities that feed flies at every refuse-heap and barn have flies. Noav the staple food of the house-fly is horse-duug. Probably at least two out of every three that scrape and preen themselves over our plates haA 7 c been hatched in a stable, Avhile selected samples of stable manure are reported to assay 2,000,000,000 individuals to the ton. Luckily they are selected -and not average samples; but they show \yhat one neglected horse may do for a neighborhood.; Crude oil sprinkled over an ordinary refuse heap Avill check the groAvth of larvae in it; but, unfortunately, this device is debarred when manure is said to be xised as a fertiliser, since groiving crops seem to realish coal oil as Tittle as insects. There is nothing for it, then, but to fall back 011 netting, arid to screen the fly’s viands as carefully as Ave screen our OAvn. Above all, for the ordinary decent household there is the garbage-bucket. In theory, the garbage is removed at least once a week; and since the housefly after the egg is laid takes ten days te come to maturity, no fly should ever hatch out in the family refuse. Practically, ho av ever, the SAvili-pail never gets really emptied at all The collector tips it over, prods the consents Avith a stick, gives it a couple of knocks. So much of tlie contents as does not happen to fall out remains to inoculate the next Aveek’s refuse Avith larvae already half-grown. The young maggots are pretty small and a hundred or tivo AA’ill remain in a cupful of Avaste at the bottom of the bucket; for, unlike the Avinged adult, they are negatively pliototropio and shun the light. Before the next garbage collection' these tiny maggots are fullgroAvn. Then they—well, they make' more impression on the observer. Of course, one ought to screen stables and barns. Quite as much one ought to screen receptacles for garbage. A counsel of perfection Avould be to haA r e, in the place of the usual Avooden bucket, tAvo metals ones, to employ them alternately, and to have one off duty clean. The housekeeper Avho would do that Avould probably see a portion of her share of flies migrate to the more odorous premises of her less tidy neighbor-;.. The fly can be put doAvn. The proof is that it -has been done. Speaking rashly, there are no flies in England; at least, there are so feAV that the inhabitants do not think it Avorth Arhile to screen their dA\ r ellings. The reason is the simplest—the tight little island is kept clean. Fifty years ago flies were a nuisance in England; thought not the plague they are here, for no other really civilised country Avas ever quite so dirty as the United States of America. This nuisance is pretty completely abated. In fifty years England has been SAA'ept and garnished, and the flies have' starved.