Extraction of Blood-Vessels, etc.— The pro hibition of the blood, the fat and the nervi ischiadichi necessitates the careful extraction (nikkur) of certain blood-vessels, mem branes, fat layers and tissues, sinews and fat fibres from various parts of the body (Shul. Aruch, Yore Dells § 65.) English-speaking Jews call this process of extraction "porging," a word derived from the Judmo-German "por schen." The process is very elaborate Encyclopedia,) article "Porging)) in the case of animals. It is, however, very simple in the case of fowl, where the prohibition neither of fat nor of the nervi ischiadichi obtains.
Salting, etc.— There still remains one further process Melihah (salting), before the meat is fit for food, and that is the soaking and salting thereof to remove the surface blood Salt also came on the altar with sacrifices (Lev. ii, 13; Ezek. xliii, 24). The hygienic importance of Melihah is referred to under section Health Laws.
Products of the Prohibited.— Not only are the unclean and the diseased animals prohibited but all their products. Thus the milk and cheese of both unclean and diseased (Trefah) animals are prohibited. Milk and cheese should not therefore be purchased in the general market without superintendence. Human milk is prohibited for the adult and even for the child who has once been properly weaned. So the eggs of unclean birds and all eggs on whose yolk a drop of blood is found are prohibited. In like manner the roe of an unclean fish can not be eaten. Honey, however, is permitted, as it is not regarded as a product of the bee, but simply as the nectar gathered by the insect (Shul. Aruch, Yore Deiih § 81). In the case of any mixture of the forbidden and the per mittecl,—if the taste of the forbidden object be discernible, then all is forbidden. So cheese which has been curdled with a prohibited rennet is entirely prohibited, and some superin tendence ought to be exercised over the manu facture of cheese.
Meat and Milk.— The threefold repetition of the command "Thou shalt not seethe the young in its mother's milk" (Deut. xiv, 21) is traditionally interpreted as referring to the threefold prohibition of cooking meat and milk together, of eating this mixture or of deriving any benefit from it. The interpretations of the command have been many and varied, but two predominate, and have certain justification. Philo construes it as an ethical law similar to (Deut. xxii, 6, and Lev. xxii, 28), denouncing cruelty to animals and intended for the moral discipline of the people. The milk that was set apart by nature for the nourishment of the young should not be used as the medium in which the young is seethed. Maimonides ex
plains the prohibition as directed against an old heathen custom or magical rite of propitiat ing the nature gods by sprinkling the fields with this meat and milk broth. This ex planation of the prohibition has also been ad vanced by Spencer and Cudworth and has re ceived some support from modern authorities. Meat and milk are never partaken of together at the same meal, sufficient interval being al lowed, if the meat has been eaten first, for it to be digested before partaking of milk. The pro hibition refers with equal force to any prepara tions in- which meat or milk enters (Shut. Aruch, Yore Deal §§ 87-97).
Vegetable Dietary Laws.— Not all the food laws concern themselves with meat. There is the injunction concerning Orlah which forbids the use for food of the fruit of a tree in the first three years of its growth (Lev. xix, 23 25).. The yield of the fourth year, or its money equivalent, was brought to Jerusalem and used for special rejoicing and feasting. The prohibition of the fruit crop of the first three years continues binding to the present day. Another law of somewhat similar character is that of Hadash which prohibits the eating of the new corn until the time of the offering of the Omer (Lev. xxiii, 9-14). The sowing of mixed seeds in a vineyard is prohibited (Dent. xxii, 9). Should, however, the prohibition be transgressed, then the produce cannot be used for food. But the most important vegetable dietary laws are those of Hametz and Matzah commemorating the Exodus from Egypt. Dur ing the eight days of the Passover festival no leaven (Hametz) can be eaten and none may be permitted to remain in the house (Ex. xiii, 7). There is furthermore the positive law that un leavened bread (Matzah) shall be eaten.
Heathen Food Another group of dietary laws are either prohibitive of the ob j ects of idolatrous worship or of intercourse between Jews and idol-worshipers. The most important of these refer to the use of wine. Wine that has been consecrated to an idol is absolutely prohibited. But even the ordinary wine of the heathen is prohibited, partly be cause of the suspicion that he may have conse crated it to his idol but also to create a social barrier that would make the possibility of inter marriage more remote (Ab. Zarah 36B). Fur thermore wine that has been touched by an idolator, though belonging to a Jew, will be under suspicion of having been idolatrously consecrated and its use prohibited. The gen eral stringency of the regulations is, however, influenced by the specific conditions of social environment.