The Jewish dietary laws were not instituted consciously for hygienic reasons. Notwithstanding this, the actual hygienic and sanitary aspects of these laws must form an essential basis for their scientific evaluation, and it is from this standpoint that they are reviewed in this article.

The Hebrew definition__"Kasher" denotes any foodstuff which by virtue of its salutary nature is conducive to the proper nourishment of the human economy without giving rise to any disturbance after being ingested. "Treifa" signifies anything, which, possessing more or less toxic or unsalubrious properties, is unable to sustain the wants of the organism, and is also instrumental in the possible creation of symptoms directly or indirectly attributable to the food partaken.

In short, "Kasher" means wholesome and sanitary, while "Treifa" conveys the idea of anything that is directly unhealthy, toxic, and insufficient for the needs of the human body, or is indirectly capable of engendering ill effects.

The following constitutes a discussion of the interdicted articles of diet barred from the dietary of the Jew. In order to do this it is necessary to resort to a consideration of certain zoological features bearing on this question as well as theories belonging to the realm of evolution.

Evolutionary zoology teaches that animal organisms of a simple anatomical construction are less adapted to alimentary purposes than those of a complex constitution; hence the various Reptilia, Mollusca, and Crustacea are not only insufficient as articles of diet, but also give rise to manifold forms of intoxication. A variety of micro-organisms infest these lower forms of animal life. These have a weak resisting power and are endowed with a low vitality. Animal organisms of this type are decomposed with great facility and become a prey to bacteria. The simpler an animal is constructed the less fit it is for the sustenance of the human body, the speedier it undergoes decomposition, and the more prone it is to create constitutional disturbances.

There are four species of locust which the Bible permits as food; but their nomenclature is so involved and their exact identity is so doubtful that we are at a loss as to the kind of locust specifically meant.

The tortoise is known to carry in its crusty covering a number of microorganisms, and there are cases on record of deaths which are traceable to the eating of turtle flesh. The snail, mussel, and the different varieties of crabs are species to which the above is equally applicable.

The Bible forbids the consumption of fish which do not possess fins and scales. Here again we are forced to resort to the evolutionary doctrine, which teaches that all aquatic creatures which have squamous tunics are of a higher type than those which have no such appendages. The fishes having fins stand high on the ladder of evolution. To reason from an a priori assertion, it would seem that they are more suitable as an article of diet than those that are deprived of the above requisites. They are easy of digestion and of greater nutritive value than the scaleless inhabitants of deep sea or fresh water. An adequate example is the classical fact repeatedly rehearsed in all books on hygiene and sanitation, namely, the communicability of typhoid fever through the medium of the oyster, which belongs to the order of of mollusca, an intermediary group of the above class. The eel is another member of the foregoing genus; it is a so-called creeping fish, is difficult of digestion and although relished by many, can lay no claim to being a wholesome and nutritious food.

Another very important feature which must be mentioned in connection with the discussion of animal evolution is that the primordial organisms have almost all subsisted upon a flesh or protoplasm-devouring regimen; they have all been carnivorous animals. As they, however, ascend the scale of progression we find that they have also acquired the tendency to subsist under vegetable diet; they were gradually transformed into herbivorous animals. We know that the fiber of animals, the recipients of an exclusive nitrogenous food, is extremely tenacious, requiring much heat to render it pliant and masticable before it can be pronounced fit to reach the table. On the other hand, animals which depend upon vegetables for their nutrition possess delicate and tender muscular fibers, demanding comparatively little culinary effort at preparation. The latter class of animals harbor a special digestive apparatus, and require very little labor in digesting their food. From this we may easily deduce that the herbivorous animals are of a higher type, and thus more adapted to the diet than the carnivorous animals, whose fiber does not lend itself as readily to culinary purposes; this would substantiate the evolutionary doctrine that complexity tends toward progression, and simplicity of organization and structure indicates a primitive developmental type.

Mammalia permitted dietetically must be both ruminant and cloven-footed. One prerequisite alone does not suffice. These species of animals are all herbivorous.

The muscular fiber of the rodents such as the hare and rabbit is very tenacious. Special preparations are necessary before they can be regarded as a fit dish. Their flesh is one of the most indigestible of animal tissues, and, as such is biblically prohibited.

One of the most dangerous, intractable, and incurable of diseases is "trichiniasis" which affects the swine due to its habitat of squalor and filth. Thelminthiae, or worms, as taenia solium and taenia mediocanellata (different varieties of tapeworm), as well as other parasitic forms may infest the intestines of those who partake of the flesh of this animal.

Domestic fowls exhibit delicate muscular fibers, while those in the wild state yield a comparatively tenacious musculature. The flesh of the domestic chicken, for example, is more savory and digestible than that of the wild duck, the latter being an omnivorous fowl, while the former is a herbivorous bird. The following birds are pronounced unclean: eagle, ossifrage, osprey, vulture, raven, ostrich, night-hawk, cuckoo, hawk, owl, swan, pelican, gier-eagle, stork, heron, and lapwing.

Albumen is an essential and necessary ingredient upon which life and its successful continuation depends. Milk harbors the most digestible form of albumen, viz., casein-albumen. Animal albumen, which is found in every animal texture without exception, necessitates a greater effort on the part of the stomach and requires more time for its complete digestion than casein-albumen.

Hence, a diet of mixed albumens both animal and liquid albumen (the latter as represented in milk)__taken at one meal burdens the digestive capacity of the stomach, and puts a heavier peptogenic or digestive task upon it. The consequences accrued from it may in time assume formidable proportions, such as apepsia or indigestion, atony of the stomach, and a host of manifold disorders of the digestive tract. An individual partaking of the various forms of albumen at one meal would eventually encounter some distress or disturbance in the digestive organs, which may subsequently lead to more serious consequences.

There is a disease afflicting both man and beast, which in the former constitutes a terrible scourge. This affliction is rightly termed "the white plague of mankind," Tuberculosis. One of the potent sources of infection is the meat and milk of consumptive animals. The cow is peculiarly susceptible to the bacillus of tuberculosis. Inspection in this direction is as yet imperfectly carried out. However, the system of ritual meat inspection as practiced by the Jews is the most thorough, painstaking and efficient extant, as it prevents infected meat gaining access to the butcher shop and hence to the table.

The Bible also interdicts the use of cattle which have perished from disease, because as soon as an animal succumbs to disease of whatsoever kind, it becomes the harboring place of numberless and nameless low forms of animal life.

Meat kept over three days is very rarely used by the Jews, unless the same has been well washed, and then only in exceptional instances. No such thing as indefinite or prolonged refrigeration or cold storage is permitted. The meat that comes to the Jewish table is fresh, clean, wholesome, and free from pathogenic organisms. In short, it is "kasher."

The profound wisdom of the Bible becomes apparent from the foregoing. Its ordinances aim at prevention. Its precepts are in accordance with the doctrines of modern sanitation, and its regulations compatible with the dictates of hygiene. The Bible is the pioneer of the sanitary sciences of today.