containing kitchen refuse must be kept tightly closed or screened, and refuse of any kind must not be thrown out into the back yard to decay. The reason for this cleanliness is to prevent the female house fly from depositing her eggs upon the material which is to provide food for the maggots.

Permanent preventive measures will always be far less expensive in the end and also very much more effective than the application of temporary methods in the form of insecticides, which must be applied over and over again with continuous expenditure of time, labor, and money.

CLEANLINESS ABOUT STABLES.

The writer has been called on frequent occasions to explain the presence of many flies about stables which were said to be in "perfect condition." Three instances may be mentioned. In one case the inside of the stable was in good condition, the manure being thrown out in a heap and removed every four or five days. It was said that surely no flies could develop under such conditions, inasmuch as it requires ten to twelve days to become full fledged flies. The error is evident at once, namely, it requires only four or five days for the maggots to reach their full growth, after which many of them migrate from the manure pile proper into the loose ground underneath or into near-by débris. Removing the manure pile every four or five days therefore did not eliminate the trouble; indeed, it was shown that hundreds of maggots were present in pockets under the site of the pile, and furthermore, 2,561 pupa were taken from one and three fourths pounds of manure collected at random from underneath a platform leading from the stable. Thus there remained no further question as to the source of the flies in that locality.

The second instance seemed to have a better basis for doubt. In this case the stable was provided with a cement floor with good drainage and the manure was thrown every morning directly into a cart and immediately hauled away. Now, where did the swarm of flies come from? Adjoining the stable was a small lot in which the horse was frequently set free. No attention, of course, was paid this open lot where manure, kept fairly moist with urine, collected and here literally thousands of house fly maggots were developing. Again the problem was solved and the horse lot was thoroughly scraped and thereafter kept clean.

The third instance was easily explained in part and eventually entirely elucidated. In this case it was a certified dairy. Flies were abundant; where did they come from? The horse stables were found to be partly floored with cement, but the stalls were made of wood planks with wide crevices between. In these crevices manure had collected abundantly, and maggots were found there in large numbers. But that was not altogether sufficient to explain the situation. It is, of course, well known that cow manures are not so highly favorable as breeding places for house fly maggots, and none were found. But there is no excuse for not properly disposing of cow manures, inasmuch as the horn fly develops here, one of the most troublesome cattle pests. These manures when piled up are also a fairly good location for house flies. Further search, however, brought to light the fact that the cattle were being fed at that time on "brewers' grain," much of

which remained unconsumed and was dumped upon the field as waste. These piles of waste "brewers' grain" were found to be literally alive with fly larvæ, and again the mystery was solved. These three instances will suffice to make clear the range of breeding places and also the necessity for careful inspection of premises.

MANURE BINS.

There must necessarily be some way of disposing of manures from stables. The old method of merely throwing this material outside the barn door and allowing it to accumulate there indefinitely is not only

FIG. 4. An inexpensive but effective wooden manure bin with concrete base. The photograph shows the last manure pile in the yard.

disgusting, but should be considered a criminal act punishable by fine, as it is already in a few of our American cities. The open manure pile must be abolished. The effectiveness of fly-tight manure receptacles has been demonstrated beyond question; it only remains to be decided as to the most practical form which will carry with it the least expenditure of time and money in construction. Several forms of receptacles in use in Berkeley, California, are illustrated herewith. Where only one horse is stabled a simple galvanized iron garbage can has been found very useful and convenient, or even a tight barrel covered over with a tightly fitting lid. The contents of these cans or barrels is removed once or twice per week, either by the city scavengers or by gardeners for fertilizing purposes. Where many horses are stabled, as in a livery stable, a larger receptacle must be provided. In such cases a closet or bin can

be constructed at a small cost, which is satisfactorily offset by the absence of the fly nuisance. Such a closet may be built in one corner of the stable, with a small screened door through which the manure is thrown when cleaning the stalls (providing also for ventilation), and an outer door giving access to clean out the closet once or twice per week. Or a closet of about the same construction may be built in the form of a shed or lean-to connecting with the stable by means of a small screened door, as above. Where it is not convenient to construct a lean-to of this type because of sliding doors or other obstructions, a bin may be substituted as shown in the figure. (Fig. 4.) The illustration

FIG. 5.-Photograph of a concrete manure bin.

While very substantial the bin is highly impractical, inasmuch as manure must be lifted out in removing it, and the bin is too far away from the stable. The metal lid also is clumsy. shows the bin open ready to receive the manure; the bolted door shown in front swings up to allow access in the removal of the manure. The use of a concrete floor built directly upon the earth is strongly recommended, and the wood inside should be well provided with a heavy coat of tar. Any of the closets or bins already mentioned can be constructed at a cost of from twenty-five to thirty dollars or less, which is trifling when the permanency and satisfaction is considered.

Concrete bins and pits are also used with much success, but, of course, are more expensive. A type of concrete bin used at one of the fire engine houses in Berkeley is illustrated. (Fig. 5.) This bin is not so conveniently constructed as it should be, inasmuch as it is unhandy to remove the manure. Concrete pits covered over with a metal top and

built in some dark corner of the stable are also highly effective. The darkness will help keep away the flies.

On the farm or ranch it is often possible and certainly advisable to remove the stable manures every morning, by merely backing a cart to the door, depositing therein the material and hauling it to the field at once, where it is scattered. The manure should in all cases be scattered upon the field. Thinly spread manure is not favorable to the breeding of flies, because proper moisture and heat conditions are wanting. Gardeners who desire to have rotted manure should protect these heaps at first by screens until the manure is well rotted, when flies will no longer breed therein.

INSECTICIDES FOR MANURE HEAPS.

The purchase of insecticides for continuous use on the manure pile would be a matter of no small cost, especially because of the tenacity of life shown by fly larvæ and the consequent strength of insecticides necessary to kill them. The cheapest and at the same time effective preparations now available must be applied in strengths two to five times that which is useful against other insects, and furthermore, the larvæ can not be easily reached buried as they are in the bedding and offal. Chemicals used to destroy the larvæ (maggots) in the manure pile may be roughly divided into two classes (1) contact poisons, and (2) stomach poisons. To the first class belong such preparations as the kerosenes (generally used in the form of emulsions) and the cresol preparations, also chloride of lime. To the second class belong the arsenicals, represented by arsenate of lead and Paris green. All of these insecticides are more or less effective, when used in proper concentrations and in sufficient quantities, but none of them can be applied with any degree of safety to man or the domesticated animals, because of either their inflammable, poisonous, or corrosive nature. We are, consequently, again forced to recognize the utility of fly-tight receptacles for the manures.

THE FLY IN THE HOUSE.

Nearly all efforts thus far to destroy the fly have been directed toward the winged insect, to either destroy it in the house or drive it away, These are certainly laudable efforts, but will only afford in all cases temporary relief. The fly continues to breed, and one fertilized female can be the progenitor of countless thousands of flies in one season. Until the permanent methods of control come generally into use the utmost care should be exercised to keep this most dangerous of disease carriers out of the house, thus properly screening both windows and doors is important. Grocery stores, fruit stands, candy shops, butcher shops, bakeries, and restaurants, which do not protect their wares from the flies, should be compelled to do so by health authorities, and patrons should insist upon this precaution. A little public sentiment in this direction will work wonders.

The use of the ordinary fly poisons is objectionable, since poisoned flies are liable to fall into prepared foods and cause mischief to the consumer. Furthermore, not a summer passes without its toll of innocent children whose lives have been lost, generally in extreme agony, by drinking some deadly fly poison. The writer has found (as already

suggested by others) that formaldehyde, properly used, forms a very good substitute for arsenical or cobalt poisons. This liquid material is rather inexpensive when used as indicated, and has the added advantage that it is not poisonous to man, and may, therefore, be used with. impunity around food; it is also one of the most powerful germicides known and is not injurious to delicate fabrics. Formaldehyde as purchased at the drug store is in about a 40 per cent solution and should be diluted with water down to 5 per cent to 8 per cent; in other words, add five to six times as much water. This dilution must now be sweetened well with sugar or other sweet. A good plan is to partly fill a shallow individual butter dish with the diluted formaldehyde and add about one fourth teaspoonful of sugar, then place the dish on the table or in the show window. The flies drink this material and die in great numbers not far from the insecticide. It is not an easy matter to control the fly in a dining-room where there is plenty of liquid material for food and drink, such as water, milk, sweets, etc., but where this can be removed in the evening and the dishes with formaldehyde substituted so that the flies will drink this the first thing in the morning the end will be accomplished much more readily. One is here taking advantage of the fact that the flies seek something to drink as soon as they awaken from their sleep.

THE CITY PROBLEM.

Communities in which a campaign against the house fly has been undertaken with determination to win have shown that the fly can be controlled. Sanitary laws, based upon the statements made earlier in this paper, must be drawn up and rigidly enforced without fear or favor. A preliminary educational campaign is highly desirable, and should be supported by the local press. A system of stable inspection carried on by instructed sanitary inspectors is essential. This method of inspection should not only bear the stamp of legal authority, but should also be accompanied by proper written as well as verbal instructions.

The house fly can be controlled without question, and without great labor or expense. The problem is simpler than many are willing to admit, but it requires coöperation and should have the willing support of every citizen. Everybody is concerned-and everybody will share in the victory and share in the saving of financial and vital losses.

FACTS THAT ALL SHOULD KNOW.

Being excerpts from an address on "The Physician in His Relation to Public Life." by Dr. James H. Parkinson, President of the Medical Society of the State of California, delivered at the fortieth annual meeting.

[Dr. Parkinson's address is a strong plea for greater activity on the part of the medical profession in those matters which concern the public health. The full text can be found in the California State Medical Journal for June. The remarkable statistics here given must make a deep impression on every citizen who has the weifare of his country at heart.-EDITOR.]

By "Public Life" I do not necessarily mean political activity, though, in our country, the terms seem almost synonymous, nor would I exclude this branch or phase of the question which more or less entwines itself with my original proposition. I mean more directly or more cogently the association with public movements, the leadership in those directly