horse, earthworm, etc., plant life would be coarse fare for bacteria. Eliminating bacterial life would be fatal, however, as plants are absolutely unable to live upon animal-food or excreta. Their nourishment must of necessity be in a mineral form. Now, if we suppose the earth to be deprived of all plant life, then animals would have to live on each other which would soon result in a speedy depopulation of animal life beginning with the smaller and weaker forms.

The septic tank, then, is a destructive furnace or a disintegrator. It demolishes complex organic matter making it into simpler chemical substances. It has a mechanical action in converting bulky matter into a finely divided state and partially into solution. It kills out some of the disease germs that enter.

If successfully operated, therefore, a septic tank makes sewage less obnoxious to look upon. On the other hand, it intensifies the smell and has little effect on the germs.

Obviously the septic tank is not a complete process in itself. It is, however, a good preparatory school. Its products are crude and unfinished but promising. Additional training meets receptive ground and progress is rapid.

To run a septic effluent of considerable volume into a small stream would befoul the stream and enormously increase its bacterial content. Added to a large stream, the effluent would undoubtedly find sufficient dissolved oxygen in the water to subdue its odor, but even here with great dilution, the disease germs are being added to the water in large numbers, and communities so doing are menacing the health of others below who come in contact with the waters of the stream.

Septic sewage taxes the oxidizing power of a stream more than an equal amount of untreated sewage because of the rapidity of its union with oxygen. Unless the stream is well supplied with oxygen, this sudden severe drain will exhaust the oxygen present. Crude sewage requires as much oxygen eventually but because of its less decomposed state it does not take it up so readily. Particles of crude sewage may be carried along for twenty hours before uniting with oxygen. Septic sewage would more likely combine with oxygen in the first half hour of its passage.

Besides disposal into a body of water not used for domestic purposes, there are two other courses open for the final disposal of the effluent. It may be applied either to agricultural land or to an artificial filter bed.

If the fertilizing value of the effluent is to be made use of, then vegetables and fruits for human consumption must not be grown on the land for fear of contamination by disease germs. Nut trees and fodder can probably receive the effluent with impunity. Truck gardens. may be fertilized, however, by subsoil drains properly laid within a foot or so of the surface of the ground.

If the effluent is small in quantity a filter bed of coarse material is out of the question because of the necessity for a continuous flow. A loose, sandy soil is the only recourse for the small disposal system. Here the intermitent flow is advantageous, and, in fact, necessary.

Filtration through two or three feet of sand very satisfactorily completes the purification problem. The unstable, odorous and germ laden septic effluent is here oxidized, made presentable to the most. fastidious sense of smell, and largely robbed of its bacterial wealth.

AN IDEAL SUMMER CAMP.

SANITATION AT CAMP CALIFORNIA.

By N. D. BAKER, Sanitary Engineer Inspector, California State Board of Health. [The excellent conditions prevailing at Camp California suggest the publishing of the following detailed description in the hope that it will prove useful to summer resorts, logging camps, and all localities in which a large number of people are gathered together for a portion of the year.-EDITOR.]

Camp California is conducted as a summer school of surveying by the Civil Engineering Department of the University of California and, from May 15th to the middle of July, from 75 to 150 men are there continuously. The University has recently purchased a new permanent camp site on Scott's Creek, near the ocean, about 20 miles north of Santa Cruz, and every effort is being exerted by the department to make the place a model of camp sanitation. It is equipped with a pipe water system, including a slow sand filter and storage tank, and with two septic tanks or cesspools to dispose of the wastes from the toilets at the student quarters and the wastes from the kitchen sinks. The ground about the camp is of a gravel formation and favorable for cesspool disposal.

Water Supply.-Most of the water is piped from a spring high on the hillside, but at times it has been found necessary to add to this from the creek. The entire supply is filtered by the process known as slow sand filtration. The filter tank has an inside diameter of 17 feet 6 inches and is 9 feet deep. The filtering material consists of 32 feet of sand and 9 inches of gravel graded as follows: 2 inches of 1-16 inch to 1/4 inch gravel, 2 inches of 2-inch to 34-inch gravel, 5 inches of 3/4-inch to 21⁄2-inch gravel. A head of 4 feet is maintained on the top of the sand. The area of the filter is 240 square feet or .0055 of an acre. At a filtering rate of 3,000,000 gallons per acre per day the capacity of the plant may be taken as 16,500 gallons per day. This is a conservative figure. At the extremely high rate of 10,000,000 gallons per acre per day the capacity would be 55,000 gallons per day. The efficiency would probably be greatly reduced if run at this rate.

The filtered water reservoir is a wooden stave tank 17 feet 6 inches in diameter and holding about 6 feet of water. Capacity 10,500 gallons or nearly two thirds of a day's supply. The filter is equipped with an orifice box at the outlet and an automatic device for regulating the flow and for showing the rate at which the water is being used at any time. Gauges show the static heads at the top and bottom of the filtering material and at various depths throughout it.

It is intended that the plant shall be used for purposes of instruction. and to this end, accurate records are kept of the readings of loss of head and rate of flow. Bacterial counts are made each day of samples of water taken before and after passing through the filter. These counts are made on gelatin plates after forty-eight hours, and the work is done at the filter house. It is interesting to note that at first the counts of the unfiltered water were consistently a little lower than those of the effluent. The latter, however, seemed to contain but one kind of bacteria, while the former we been in operation for the number of bacter

several difft kinds. After the filter has ime it is exed that it will greatly reduce

Besides the diversion line, filters and filtered water reservoir, the water system includes a line with taps for street sprinkling, a wash-place for the students and another for the faculty, toilet attachments, and taps for the kitchen sinks. The entire system was installed at a total cost of about $1,500.

Disposal of Wastes.-The toilet at the student quarters has twenty seats placed in two rows over troughs. The troughs are made of one inch redwood lumber smoothly planed inside and liberally coated with hot asphalt. Two urinal troughs each 16 feet long are made of the same material. The entire building has a smooth finish, concrete floor and is provided with hose connections for flushing. The device for flushing the closets is very simply constructed, consisting of a wooden bucket of trapezoidal cross-section. This is so balanced that, when empty, its center of gravity is on one side of the pivot and it is held upright. When full of water its center of gravity is transferred to the other side causing the bucket to tip and empty its contents. A small stream of water is kept running into the bucket continuously and at intervals empties itself into the troughs of the toilets; the intervals can be regulated by adjusting the stream from the pipe or by changing the balance of the bucket. The amount of each flush is about eighty gallons, and during the day it is arranged to flush at intervals of about fifteen minutes. At night the water is shut off. Estimating the average intervals at 15 minutes for twelve hours per day, the use of water for this purpose alone is about 4,000 gallons per day.

The

Cesspools. The cesspool for the student toilets is 7 x 7 x 5 feet lined. with 2-inch redwood and designed to hold 41 feet of sewage. effluent is drawn off through eight 2-inch galvanized iron pipes from a depth of 18 inches below the surface; the sewer enters at the same depth. These outlet pipes extend 4 inches outside the box. In making the excavation, a space of 12 inches was left on all sides and 8 inches under the bottom. This space was back-filled with stones and gravel, special care being taken to place the stones about the outlet pipes so as to facilitate seepage. The roof of the structure is two feet below the ground surface. The cesspool for the kitchen differs from the above only in size. It is 5 x 5 x5 feet, designed to hold 411⁄2 feet of sewage. The discharge from the sinks enters through a 5-inch vitrified pipe and there are 8 outlet pipes of 115-inch galvanized wrought iron.

The camp site was laid out and the water system and sewage disposal tanks were planned and built under the direction of the Department of Civil Engineering of the University of California.

PRIVIES SANITARY AND INSANITARY.

By RAYMOND Russ, M.D.

It is, indeed, fortunate that we live not only in a thinking and sensible age, but also at a time when diffidence and false modesty have been thrown aside and we are able to deal with subjects, which a few years ago would have been tabooed, frankly and without cavil. The great advances which recent years have wrought in sanitation have made this necessary. Modern sanitation is but the adaptation to practical usage of the great truths which scientific medicine has discovered, and

so many of these facts bear directly upon the individual, his habits and his daily life, that plain speaking is absolutely necessary.

All men were at one time soil polluters, and their daily functions were performed without regard to their environment; but with the growth of civilization came the development of modesty, that virtue which is now innate, and the calls of nature were done in seclusion. The privy owes its existence not to sanitary needs, but to privacy and seclusion, which have always been its important features. These considerations determined its location and its construction. Little attention was paid to convenience and comfort, and as for health, that question was never even thought of. The modesty which prompted its construction forbade its being a theme of discussion; it was a topic of conversation only for the ribald and obscene. The pestilential odors which rose from its vault in summer made it a place to be avoided as long as possible; its remote location caused a visit to it to be dreaded in the cold of winter. "Did you ever stop to consider," said a physician of long experience, "how much the modern toilet facilities have accomplished for the health of the community. In the old days it was no uncommon occurrence for people to go three and four days and even longer without a bowel movement. Think of the damage caused by the absorption of this toxicmaterial, the dull eye, the coated tongue, the jaded countenance, and the ennui and lethargy which personal negligence had engendered."

A town in establishing an adequate sewage system, takes the primary and most important step in its physical betterment; it can do no other single act which will be of such great benefit to all. An adequate sewer system is the basic principle of sanitation. Where the removal of sewage to large bodies of water has been impossible the septic tank has accomplished wonders. Built on bacteriological facts, its use is but little understood except to those who have had a good grounding in this subject. Mistakes in its construction are many and the care of the plant is frequently faulty. Notwithstanding these facts, the septic tank works so admirably and requires so little attention that its employment has proven most satisfactory. It has meant much to inland towns and rural districts, for it has done away with the dangerous cesspool and has made a good system of sewage disposal possible.

The privy at best is a poor expedient and should be regarded as a temporary makeshift. But more than this, the average privy is an element of danger, and it has been only in recent years, when sanitary science has made such strides, that its bearing on disease and its propagation has been understood. At present it must be regarded as one of the greatest menaces to the health of the community. Now that we appreciate the dangers of soil pollution, the contamination of water supply, the great rôle which flies and other insects play in the dissemination of disease, the evils which arise from irregular habits of visiting the toilet, the case against the outhouse becomes a strong one.

No better example of the evils of soil pollution can be cited than the dreaded hookworm disease which has wrought such havoc among the poor whites of the South and has been such a factor in reducing their social status. It is a condition which is easily controlled by sanitation and fairly easily eradicated in the individual.

Only a beginning has thus far been made in the study of the parasites which infest the human intestines and the diseases to which some of them

give rise, as hookworm, tapeworm, amoebic dysentery, and which they readily transmit. Sufficient, however, is known to make apparent the great dangers of soil contamination and to make the safe disposal of human excreta a matter of the greatest importance. Add to these the bacterial diseases, such as typhoid fever, and the importance becomes

apparent of protecting the excreta from flies and from dissemination by rain, and by chickens and swine, and depositing it in one place from which it can be removed at frequent intervals and properly disposed of.

The vault privy which is in general use does not guard against these evils. Moreover, it is too often built in close proximity to the well, and contamination of the water supply from this cause is not uncommon.