CHAPTER II. THE HYGIENE OF HABITATIONS. (Part 8)

favorable medium for the develojHnent of micro- organisms which swarm in the meat or may gain access later. The resulting dccompo>ition and organic changes necessarily cause the m«at to deteriorate 104 HYGIENE OF FOODS AXD FOOD SUPPLY and render it unfit for food unless bacterial action is inhibited by placing the meat in a condition ren- dering the development of bacteria and putrefaction unfavorable. The rapidity of deterioration depends on the condition of the animal from which the meat was obtained, the cleanliness of the process of preparation, and the place in which it is kept. Infection by Persons and Places. — In addition to the foregoing sources of deterioration, meat may be directly infected with pathogenic and other bacteria by the persons who handle it and take part in slaugh- tering, skinning, dressing, cutting, manufacturing, and packing. Food may also become infected in the various places tlirough which the meat must pass in the process of manufacture. Adulteration of Meat. — Meat adulterations may con- sist in: 1. The addition of foreign substances reducing, lower- ing, or injuring the quality of the food. 2. Partial or entire substitution of an inferior substance. 3. Extraction of some of the valuable substance from the meat. 4. Coloring, coating, or otherwise changing the appearance of the food, concealing its poor quality or making it appear better than it is. Characteristics of Good Meat. — Good meat is uniform in color, neither too red nor too pale, firm and elastic to the touch, moist but not wet; it does not pit nor crackle on pressure, and has a marbled appearance. It is free from unpleasant odor, its juices redden MEAT AM) MEAT Sll'l'LY 105 litiiius paper slightly. Tlic fat is (inn and docs not run. Bcft' is Itriulit rc(l. more niarl)l('<I than an- otlicr meat. \v\\ is ])alf and los firm to the toudi. Mutton is dull red, firm, and its I'at white or yellowish. Horse meat is coarse in texture, dark in color, without layers of fat in the nmscles; the fat is yellowish and runs down in drops when tiic carcass is hun^^ up. and has a j)C(iiliar sweetish odor and taste. Preservation of Meat. — Postmortem put-refactive changes due to the development of bacteria can be prevented: (1) By rigid asepsis and the cleanliness of those who handle the meat and by careful attention to sanitation in the places in which meat i)roducts are prepared. This prevents the bacteria from gaining access to the meat. (2) By the storage of meat under conditions that are unfavorable to the life and devel- opment of bacteria. These are cold, dryness, and condimental or partly chemical preservations. (3) By destruction of all the bacteria, /. e., by sterilization of the meat by heat. Coh] Storage.— Co(\ storage of meat does not kill bacteria, but inhibits their growth, and keeping meat in colfl storage or freezing may preserve it for a long time. The common opinion that meat may be kept in cold storage indefinitely without injury is wrong, f(^r meat certainly deteriorates if it is kejjt at a low- temperature for more than two or three months. On thawing, frozen meats deteriorate very rapidly, and they have been known to produce toxic symptoms on ingestion. As an auxiliary means of preservation for not too |)rolonged periods cold is a valuable preservative. 106 HYGIENE OF FOODS AND FOOD SUPPLY Drying. — Drying of meat is an old method of pre- serving it, and may be a valuable means of preserving the meat fibers; but they should be rendered very dry, or in the form of powders. Drying may be accom- plished in the sun, and is very slow, or it may be done artificially. Its usefulness is necessarily limited. Condiviental Preservation. — Condimental preserva- tion of meat consists in preserving it by the aid of salt, sugar, vinegar, and other condiments, either in dry form (with salt) or by the wet process (pickling in vinegar, etc.). These condiments do not kill the bacteria, but they effectively stop putrefaction and may preserve certain meats for long periods. Smoking. — Smoking meat renders it not only com- paratively dry but also impregnates it with the creo- sote of the smoke, which serves as a valuable means of preservation of certain kinds of meat. None of the above methods of preservation destroy parasitic ova, or all the pathogenic germs which may be in the meat, and all except cold render the meat less digestible, and somewhat alter its texture, appear- ance, and taste. Chemical Preservatives. — The use of chemical pre- servatives, such as borax, boracic acid, sulphite of soda, and others is very reprehensible, and is justly pro- hibited by federal and municipal sanitary legislation. The objections against chemical x>reservatives of any food may be summed up as follows : 1. All chemicals used for preservation are more or less toxic, and their ingestion injurious to health, especailly if habitually used. 2. By the use of chemical artificial preservatives MK \r \ \ I) mi: AT sfi'ri.y l(i7 inferior meats and ])n)(liuts ami meat wliicli is partly (lerdinposcd ma' l>e so (lis<];uise(l as to Ix- sold as fresh and unspoiled |)ro(lncts. llrat. — Heat preservation of meat is the only etieetive and absolutely reliable method of preserva- tion, beeause it kills and destroys all entozoa and pathogenic jjerms, and thus reii<lers the product sterile and absolutely safe. For domestic use the sterilization of meat is accom- plished by roasting;, baking, or boiling for from fifteen minutes to an hour. For roiniiirrrldl jnirposes the yro- cess of titt'dt iircsrrvdfion should include (1) destruc- tion of all germs by heat, and (2) enclosure of the l)r()duct in hermetically closed sterile vessels in which further infection is prevented, thus permitting the food product to be preserved for indefinite j)eriods. This process of meat preservation consists of "canning," and is accomplished in the following manner: (1) By selection of appropriate meat; (2) cutting it into ai)proj)riate pieces; (8) parboiling or exj)osing the meat in hot water under the boiling-point for ten to twent>- minutes in order to shrink it and lessen its bulk; (4) the parboiled meat is placed in cans or tins filled with salted soup or liquid and the cover is sol- dered on, except for a small aperture for the escape of air; (.'>) the cans are then j)lace(l in boilers or .steamers and subjected to high heat for an hour or two; (0) the oj)enings left in the cover of the can are closed and the cans are again subjected to a steam bath for an hour <»r more, accordinu to the character of the product. Sanitary Supervision, Prevention of Adulteration of Meat. The strict sanitary supervision of all tlu^ 108 HYGIENE OF FOODS AND FOOD SUPPLY various processes through which meat passes from the initial to the final product is absolutely necessary in order to render the food supply free from dangerous contamination and infections. Adulteration by sub- stitution, palming off inferior products for superior ones, and adulteration with foreign ingredients, as well as by artificial preservation by means of chemicals, may be prevented only by a rigid, thorough, scientific, and prompt municipal and federal inspection by quali- fied and competent medical officers. Poultry and Game. — The flesh of all domestic fowls, such as chicken, turkey, geese, duck, and of some wild fowls, is used for human food. Vacher^ gives the following characteristics of healthy poultry and poultry meats: "Healthy poultry are active, bright, dry in the eyes and nostrils; the feathers are glossy and elastic, and the combs and wattles are firm and brilliant red. Age is indicated by duskiness of comb and gills, dulness, fading, and brittleness of feathers, raggedness of feet and size of claws. Good poultry should be firm to the touch, pink or yellowish in color, fairly plump, should have a strong skin, and a fresh, not disagreeable odor. Stale poultry loses firmness, becomes bluish in color, green over the crop and abdomen; the skin readily breaks, and the bird has a disagreeable odor." "Drawn " or "undrawn" are terms used to indicate the removal or presence of the internal organs of poultry offered for sale. Undrawn poultry decom- poses sooner on account of intestinal putrefaction. Cold-storage undrawn poultry may become dangerous ^ Food Inspector's Handbook. Mi:.'r AM) MhWT SI I'I'LY 109 Xo lu'nltli 1)' its (lotcrioration. As poiiltry can be (»l)taiiu'(l at all times there is no tfood economic reason why it sluuilii l>c |)larc(i in co|<l storage for loii^ |)crio(ls, and the practice is repreiu-nsihlc. The cii>tom of keeping poultry' or game for a certain time nntil it is "ripe, " or "gamey," and partly decomposed, is dangerons to health. Forced feeding does not >eem to produce any pathological conditions in poultry , and even the "fatty liver" of forcibly confined and fed geese, in the nnich-prized delicacy "pate de foie gras" does not seem to afTect the gourmand injuriously. Live poultry is subject to many and various diseases which render the meat \mfit for use, and the necessity of rigid antemortem inspection is apparent in this as well as in other meats. Fish Foods. — A large variety of sea and fresh-water fish are used for food, l-'ish are allowed to die by being (lej)rived of oxygen. Fish should be used in season, should be fresh, firm, and cla.stic to the touch. Fresh fish may be recognized by the rigidity due to rigor mortis, the freshness and red color of the gills, the moist, clear eye, and not disagreeable odor. Frozen fish is not palatable, and decomposes very rai)idl' on thawing. Many cases of i)oisoning. includ- ing ptomain poisoning from eating .■>tale fish, are on recoril. The eating of ceiiain shell-fish, crabs, lobsters, and oysters is at times fraught with danger to health, and many ca.scs of wholesale poisonings ha'e been reported. Oysters sometimes are purveyers of typhoid fever, when the' are grown near larire town> in waters that no HYGIENE OF FOODS AND FOOD SUPPLY are much contaminated by sewage containing typhoid germs. The danger from oysters is the greater in that they are very often eaten raw. Fish are preserved by smoking, drying, salting, pickhng, and also by canning. The sanitation of the establishments where fish are prepared for canning should be the same as that for the manufacture of meat products. MILK AND DAIRY PRODUCTS. Importance of Milk as a Food. — Of all the various foods used by human beings milk is the most im- portant. Milk contains all the elements of food necessary for the nutrition of man, and it contains these elements in a right proportion. ]Milk is the only food of millions of infants and children deprived of the breast; it is the principal food of the sick, of invalids and convalescents, and it is a part of the food of all people at all times. The great importance of milk and milk products as a food and the magnitude of the milk industry make it of paramount importance that they should reach the consumer in as clean and as pure a state as possible. This, however, is almost impossible for the following reasons: (1) Distance, (2) time, (3) the nature of the product, and (4) contamination. Distance. — In the milk supply of cities the distance of the producers from the consumers is necessarily great. New York City obtains its milk supply from about 44,000 farms located in six States and within a radius of 400 miles from the city. MILK AM) y>.l//i'}' rifnlXCTS 111 Time. — Tlie city coiisiiiiu'r ot" milk liiinilx vwr ^ets it less than twciitx-foiir liours old. and often tliirty- six and t"ort\ -ci^iit honrs (•lai)se l)et\vci'n inilkinji and c(»nsiinii)tion. XalKrc of Product. Milk, being an oi)a(|ue aninuil secretion voided at a temperature of the body, is easily contaminated with all kind^ of impurities difHeult of detection. Sourci's (if ('(inf(uiiiti(i(i()ii.- These are -ery numer- ous. They may he the cow. the food and water she drinks, the stable, barnyard and surrounding of the cow, the pails, cans, and various utensils used by the farmer, milkers, and handlers of the milk, and a great many other things. Character of Impurities. — The imj)urities which are found in milk may l)e ilivided under two large groups: Dirt and bacteria. Dirt. — By dirt is meant everNthing found in milk which is foreign to its composition and is not milk, which "is matter out of place." The dirt may be mineral, vegetable, or animal. The mineral dirt con- sists mostly of dust, sand, clay and earthy particles; also of certain preservative salts used for increasing the keeping qualities of milk, ^'egetable dirt is com- posed chiefly of particles of hay. straw, grain, seeds, flowers, etc. The animal dirt, which is abundantly found in milk, is mostly hair, feathers, manure, insects, flies, ova of parasites, etc. The amount of dirt found in milk is in direct ratio to the care taken in the production of milk. It is often very large. Most of the dirt may readily be seen at the bottom of vessels after milk has been left standing 112 HYGIENE OF FOODS AND FOOD SUPPLY for some time; it may also be readily obtained by the action of the centrifuge. Bacteria in Milk. — The most important impurities found in milk are bacteria. Bacteria are minute vegetable microorganisms, invisible to the naked eye, but discernible under the microscope, and are found everywhere. Bacteria are of various shapes, some round, others spiral, rod- shape, etc., and are found clinging to soil, dust, dirt, rubbish, excreta, discharges, etc. They develop very rapidly under favorable conditions, millions of them growing out of one colony. The importance of bacterial life lies in the fact that to it solely is due the process of putrefaction and decomposition, and the disintegration of all organic matter. Besides their putrefactive action bacteria may also play a more important role in the causation and trans- mission of disease. Within the last several decades it had been definitely demonstrated that many diseases, the true causes of which were hitherto unknown, were directly due to the action of certain bacteria which upon gaining entrance into the human body cause certain patho- logical lesions resulting in certain groups of symptoms w^hich we call by names of various diseases. These diseases are usually called "infectious," because they are caused by bacteria and may be transmitted from one person to another. A large number of infectious diseases are known to be transmitted from one person to another by means of food and especially milk. MILK AM) DMRY I'h'oDICTS 113 Disease Bacteria in Milk. A lar^^c mimlx-r ami many \ari('tifs ot" discax' haitt'ria may aii<l ot'teii arc toimd ill milk. Tiio sources of the disease jjerms are tlie cows, their surroimdiucs, their food and drink, the persons handling; the milk, and the utensils in which it is kept, as well as the air with which it ma.\ come in contact. Besides the disease fjerms themselves milk may be contaminated l)y the commou ^erms of i)utrefaction. These do not cause disease hy thetnselves, but they may produce toxic elements in the milk which may harm the consumers and cause certain ^astro-intestinal disturbances and "ptomain" ])oisonini:, often with fatal results. The infective bacteria which may be transmitted by milk are those of the following; disea.ses : Diphtheria, scarlet fever, measles, tuberculosis, cholera, ty])hoid fever, dysentery, cholera infantum. A numl)er of other infectious diseases have also been transmitted by milk, as has been demonstrated at various times. Milk and Infants' Diseases and Infant Mortality. — The prevalence of ^M>tro-inte>tinal di>ease> amonj: infants and children, especially durinj; the summer months, is well known. Out of a total (»f 1 ()."),. ").")o deaths of infants in the T'nited States durin^^ lUOo not less than 39,809 were due to jjastro -intestinal diseases. The difference in death-rate between breast-fed children and those fed on cows' milk in the New \ ork Infant Asylum in 1002 was very jjreat: 7.47 per cent. in the former to 03.14 per cent, for the latter. The 8 114 HYGIENE OF FOODS AND FOOD SUPPLY record of Rochester, N. Y., where Dr. Goler inaug- urated a vigorous campaign on behalf of clean milk for children, proves conclusively how a sui)ply of pure milk will reduce not only the infant mortality during the summer months, but also the general death- rate throughout the year. In New York City the death-rate of children under five years was reduced from 96.2 per 1000 during the whole year and from 136.4 during the three summer months in 1901 to 55 per 1000 during the whole year and 62.7 during the summer months in 1906. This reduction is undoubtedly largely due to the cleaner milk which is at present supplied to the city and especially to the use of the Straus pasteurized milk among the poor classes of the city. Milk and Diphtheria, Scarlet Fever and Measles. — It is not difficult to understand how milk may be readily contaminated by the germs of these dreaded children's diseases. The farmer's children, or the children or employees of the milk dealers and sellers may suffer from one of these diseases, and by their proximity to the milk, during acts of coughing, spit- ting, sneezing, or by the scaling of the skin, may contaminate the open cans of milk with the infective germ and thus transmit the disease to other children and people. A large number of scarlet fever and diphtheria epidemics have been directly traced to infected milk. Milk and Typhoid, Cholera and Dysentery. — The in- fective germs of the ^'arious diarrheal diseases, like t'phoid, cholera asiatica, and cholera infantum, as well as of dysentery, are found in the discharges from MILK AM) DML-y I'h-uDrcTS 115 tlic I)(>\v«"I> 111" infected jHTSdiis. These discharfies iii;iy cliiiU the the hjiiid, clothes, etc., of those who hiilidh- milk, and thll-^ miiii access to the milk in which these iiitccti'e mTm> (iiid