enty-seven samples, 28 per cent. of the samples tested, contained less than 100,000 bacteria per cc. About 34 per cent. contain less than 500,000 per cc., and 124 samples, corresponding to about 45 per cent., contain less than 1,000,000 per cc. In Williamsport, the weather was cold and rainy while the inspection was being made, and here the milk from all sources contained an average of 437,000 bacteria per cc., a number 1-13 as great as that obtained in all the Pennsylvania supplies, This comparatively low number is not entirely due to the weather. The municipal inspector, Dr. Richter, visits the dairies, compels the animals and barns to be kept clean and reports bad conditions to the public. Here the conditions are better than in any other city inspected, and there seems to be no doubt that this condition is partly due to the system of inspection, and all milk supplies will be very materially improved when the dairies are inspected as these in the vicinity of Williamsport are and all dealers who will not keep their herds and milk houses in a reasonably good condition are compelled to go into some other business.

In Philadelphia and New York the supply is remarkably good, especially when we consider the distance much of the milk must be shipped and the fact the city authorities are unable to inspect the herds, barns and milk houses.

The worst milk was found in Pittsburgh. The number of bacteria per cc. was four times as great as the average for all Pennsylvania, or of New York city and Philadelphia, yet the temperature was on an average six degrees lower while the investigation was made in Pittsburgh than it was in the two larger cities. Neither is the Pittsburgh milk shipped as great distances as that for the two other cities mentioned, and for this reason the milk supply should be materially better. The milk shipped to Philadelphia and New York is probably handled more carefully by the producer than that sent to Pittsburgh, and as a whole it is undoubtedly kept better after reaching the city than that of many other cities.

Before buying milk from dairies with which they are unacquainted a number of the wholesale dealers have herds examined to see that the animals are free from disease affecting the wholesomeness of the milk; they have the water and food supply examined; examine the cleanliness of the stables, milk room, cooler, cans, pails and other utensils, and ascertain regarding the freedom of employes from infectious or contagious diseases. They then handle the milk properly after receiving it at the depots.

Such an inspection should be made of all milk supplies, and in addition to this Pittsburgh, Allegheny, Altoona and Harrisburg are in especial need of such an inspection that will bring the milk to the chemical standard demanded by the law at the present time. The milk supply of Scranton, Erie, York and Reading is much better than

that of Pittsburg, Altoona, Allegheny and Harrisburg. While there is practically the same number of organisms in the milk of Altoona and Harrisburg as in that of Philadelphia and New York, the age of the milk received by the latter cities is considerably greater when received from the patrons, and the large number of organisms found in the fresh milk certainly shows a lack of cleanliness.

Dealers who make a study of their business take pains to treat their milk properly from the time of production to that of consumption, thereby always supplying a purer and more wholesome article of food than their neighbors, who, in many cases aim at one thing only, namely, that of preventing loss of milk by souring while in their possession.

The milk supply of cities which have a conscientious inspector continually at work, as is the case in Williamsport, New York, Philadelphia, Scranton and Erie, is much better than in such cities as Altoona, where there is practically no inspection.

The inspection of milk from the standpoint of filth is even more essential than that of determining its chemical purity as measured by its percentage of fat and total solids, and it seems that this is where the greatest reform should be made.

COMPOSITION OF THE PENNSYLVANIA MILK.

Of 342 samples tested for fat 64 (18.7 per cent.) were found to contain less than 3 per cent.; 41 of these were below 2.75 per cent.; 22 below 2.3 per cent.; 12 solids below 2.25 and 7 below 2 per cent.

Of 329 total solids determined 190 were below 12.9 per cent., 72 less than 11.5 per cent. and 37 less than 11 per cent.

The specific gravity of 18 out of 329 samples was below 1.029.

Of the 64 samples containing less than 3 per cent. of fat, all contained less than 12 per cent. total solids and 51 contained less than 11.5 per cent. Some of these samples were badly skimmed and some of them were watered. The restaurant milk, as a class, was badly adulterated, the average per cent. of total solids in all of the samples examined from this source (29) being only 11.33 per cent., and 13 of the samples were below 3 per cent. fat and 11.5 per cent. total solids. While 8 out of 30 contained preservatives (one was known to have been added at the milk depot), and from a bacteriological standpoint it was the worst milk examined. Restaurant milk is frequently skimmed and the cream used for various purposes.

Fifteen per cent. of the samples examined were undoubtedly watered or skimmed, and the results obtained on a number of other samples indicated that the supply was slightly adulterated. Assum ing that 15 per cent, of all the samples was adulterated, it is probable much less of the total milk supply was adulterated for the reason that the dealers who sell large quantities of milk daily usually sell a good

quality of pure milk and adulteration is practiced mostly by those who sell only a few gallons daily. These small dealers supply a relatively small number of persons and handle a small percentage of the total milk supply.

Not only from a bacteriological standpoint, but also from the point of chemical purity it is apparent that rigid city inspection helps very much to diminish adulteration and to improve our our city milk supplies.

GLOSSARY OF SCIENTIFIC TERMS USED.

Aerobes. Organisms requiring air or free oxygen for their growth. Anaerobes. Organisms not requiring air for their growth. Albuminoids. An important class of nitrogenous bodies formed by living matter. The casein of milk and the white of an egg are two common examples.

Bacilli. The plural of bacillus. Small rod-shaped bacteria.

Cocci (singular coccus).-Spherical bacteria.

Colony. The progeny of a single germ growing in an isolated medium.

Cubic centimetre.-A volume equal to 1-960 part of a quart.
Disinfect. To purify by the destruction of germ life.

Disinfectant.—Any substance used to destroy bacteria or other

germs.

Endospore. A spore formed within a mother cell by a change in the nature of a portion of the protoplasm.

Facultative. Organisms that grow under varied conditions.
Fission.-Division of a cell by direct partition.

Infection. Contamination with disease producing or any other undesirable organisms.

Infectious. Having power to pollute or taint.

Inoculation. The act of introducing micro-organisms from one medium to another.

Lactic acid. The sour principle that develops in milk by normal fermentation.

Medium. The artificial preparation in which bacteria are grown for examination.

Micro-organisms.-Any microscopic form of life, more especially the general class of bacteria.

Microbe. A microscopic organism.

Obligate.-Bacteria that require certain conditions in order to

grow.

Parasitic.-Living organisms that derive their nourishment from living matter.

Pasteurization. The destruction of germs by a temperature of from 140 to 165 degrees F.

Pathogenic.-Disease producing.

Preservaline.-A mixture of boracic acid or borates for retarding fermentation of milk or other foods.

Preservative. Any chemical used to prevent fermentation.
Saprophytes.-Organisms subsisting on dead matter.

Spores. The resisting stage of certain species of bacteria.
Sterile. Free from all kinds of microscopic life.

Sterilizer. The apparatus in which sterilization is accomplished.
Total solids. All the ingredients in milk except the water.

Tuberculin. A preparation from a culture of the germs of tuberculosis which is used to determine whether or not cattle are affected with that disease.

Tyrotoxicon. A poisonous substance occasionally formed in milk or cheese by the action of bacteria.

Vegetating. Growing. Germs not in spore condition.

APPENDIX.

In the Appendix all actual results obtained while making the investigation are given. In the classification, all samples selected at places retailing milk only are placed under "milk depots," but when milk and other things are offered for sale at the same place, the place is spoken of as a "variety store." In samples 1 to 176, inclusive, some of the places of selection referred to as milk depots should probably be called variety stores on account of the sale of other things, which were not noted at the time.

Samples 1 to 36, inclusive were selected in Philadelphia.
Samples 37 to 70, inclusive, were selected in Reading.
Samples 71 to 101, inclusive, were selected in Harrisburg.
Samples 102 to 133, inclusive, were selected in York.
Samples 134 to 176, inclusive, were selected in Altoona.
Samples 177 to 229, inclusive, were selected in Pittsburgh.
Samples 230 to 246, inclusive, were selected in Allegheny.
Samples 247 to 277, inclusive, were selected in Erie.
Samples 278 to 304, inclusive, were selected in Scranton.
Samples 305 to 330, inclusive, were selected in New York.
Samples 331 to 352, inclusive, were selected in Williamsport.