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In Western countries people adopt a vegetarian or vegan diet for a variety of reasons, and though their numbers appear to be increasing, vegetarians and vegans are a minority of the population. However, the world scene is very different, for a large proportion of the world's population has a near vegan diet. This kind of diet is almost always associated with malnutrition often involving deficiencies of energy, protein or specific vitamins. It might be thought that eradication of malnutrition would best be achieved by promoting a western‐type omnivorous diet. This would involve increasing production and consumption of food from animal sources, but it is doubtful if this would be either economically feasible, or nutritionally acceptable. It seems important therefore to establish whether a good vegetarian or vegan diet is consistent with health, and what effects the diet has on commonly used indices of nutritional status.

If it is a fraud to dye an unripe orange to make it look ripe, why should it be permissible to dye winter butter to make it look like summer butter?”, he says. Or one might add, to dye a biscuit brown to imply the presence of chocolate or to colour a cake yellow to simulate the addition of eggs? Our third heading is, What? What colouring matters should be allowed, and upon what conditions? Great Britain is the only leading country which has not a legal schedule of permitted colours. In this country any colouring agent may be added to food, except compounds of antimony, arsenic, cadmium, chromium, copper, mercury, lead and zinc. Gamboge, picric acid, victoria yellow, manchester yellow, aurantia and aurine are also prohibited. The addition, however, of any other colouring agent which is injurious to health would be an offence under the Food and Drugs Act. Other countries, including the United States of America, France, Canada, Australia, New Zealand, Italy, Spain, Sweden and Denmark have drawn up lists of permissible colours. And so the question arises—is it preferable to draw up a list of permissible colours or one of prohibited colours? It is obvious that if only certain colours are prohibited the remainder may be legally employed so long as they are not injurious to health. Thus a colouring agent may be used for a considerable time before it is proved to be injurious, whereas, if only‐certain colouring agents which have been previously proved to be non‐injurious were permitted, this risk of possible danger to health would be avoided. There is no doubt that in many cases proof of injury to the health of the human being is difficult to obtain. Much of the work that has been carried out to establish whether a particular dye is harmless or not has involved the use of dogs as test subjects. This does not appear to be a very satisfactory method of testing, for obviously dogs may react very differently from human beings towards chemicals. A dog's digestive powers are stronger than those of humans. No one would think of suggesting that bones are suitable food for humans just because dogs love them! Matta found that the capacity to depress the human digestion is possessed not only by poisonous dyes but also by dyes which he had proved to be non‐poisonous to animals. In bacteriology the addition of very small amounts of certain dyes to the culture medium will retard the growth of particular organisms and therefore it would seem possible that some dyes might adversely affect the action of enzymes in the body. So it would seem of importance that, if possible, all colouring matters, before being permitted to be used in food, should be proved by a competent authority to be harmless to human beings. If the effects of colouring matters upon the human digestive processes cannot be easily carried out in the body then it might be possible to perform such tests in vitro, using artificial gastric juice. It may be argued that the proportion of colouring matter added to food, ranging from about 1 part in 2,000 to about 1 part in 300,000, is so small that any particular colouring agent would need to be a deadly poison before any appreciable injurious effect upon health would occur. This argument does not, however, take into account the possible injurious effects which may be caused by the frequent ingestion of colouring matters which may have but mild toxic properties. It is known, for instance, that many synthetic colours have marked antiseptic properties even in highly diluted solutions, and therefore they may adversely affect the digestive processes. In any case, surely it would be wiser to eliminate all risks by requiring that official physiological tests should be carried out upon colouring matters before they are permitted to be used in food. One has to safeguard not only the healthy person but also the very young, the old and those who are of a delicate constitution. A harmless colour has been defined in Canada as one “which will not retard digestion nor have special physiological effects when consumed in quantities corresponding to 2 grains per day per adult.” The Departmental Committee in its report on “The use of preservatives and colouring matters in food,” published in 1924, stated that “It appears to us that definite evidence from direct experiments should be obtained as to the harmlessness of a dye before its use should be permitted in food. We have therefore come to the conclusion that a list of permitted colours should be prepared and that no colours other than those in such a list should be allowed to be used in the preparation of food. The list should, in our opinion, be prepared by the Minister of Health and issued by him, provision being made for the consideration of claims advanced by traders for the recognition and approval of additional colours on satisfactory evidence of harmlessness. We do not think that action such as this should seriously embarrass manufacturing interests, or is a course on which it is unreasonable, in view of the importance of the subject, to insist.” Yet, in spite of these recommendations of the Committee, no list of permitted colours was passed into law, and one wonders why. One argument against the drawing up of a list of prohibited colours is that even if a non‐prohibited colour is proved to the satisfaction of a given Court to be injurious to health that decision is not binding on other Courts and so there may be a lack of uniformity. A certain colour may be permitted in one town and prohibited in the next, which fact might add to the difficulties of the large scale manufacturer whose products are sold over a wide area. The leading manufacturers of dyes for use in food no doubt exercise great care in their preparation and such products are normally free from objectionable impurities, but it is possible that other dyestuff manufacturers are not so particular concerning the purity of their products. For instance, about 1938 a firm was fined for selling “Damson Blue” containing 540 parts of lead per million. Therefore it would seem necessary that some official control over the dyes that are sold for use in food should be introduced. The manufacture of some dyes involves complicated processes, and it is stated that in the production of one particular colour over 100 different chemicals are used and thirty different reactions, occupying several weeks, must be carried out before the finished colour is produced.

Whatever views may be held with regard to the question of the total prohibition or otherwise of chemical preservatives in foods, there can be little doubt that the broad theory underlying the recommendations of the Departmental Committee is perfectly, sound and consonant with the best interests of the public and the honest manufacturer. The use of chemical preservatives of any kind is undesirable, and if permitted at all, such preservatives should be restricted to substances which are not foreign to the human body. Referring to the various articles and letters which have recently appeared in The Times, Professor F. Gowland Hopkins, D.Sc., F.R.S., F.I.C., observes:—

It has been held not infrequently that of the influences which together mould the individual and determine his or her value as a social unit those of heredity are so prepotent as to leave little room for those of the environment. By others this view has seemed to involve unjustifiable pessimism. You will, I think, admit that in the past when there was little objective knowledge to bear on such questions, current views were largely decided by that ingrained difference in social outlook which has divided and still divides human opinion on so many other fundamental questions. Those who are naturally inclined to justify privilege, and who have felt instinctively that class distinctions are a social necessity founded on nature, have been tempted perhaps to emphasise too exclusively the unmistakable influence of heredity; those to whom a different outlook is natural have wished to believe, not, of course, that all are born equal as the eighteenth century philosophers declaimed, but that in favourable environments individuals tend to display greater equality of capacity.

We have on many occasions drawn attention to the all too prevalent fallacy of judging the nutritive and dietetic value of foods solely by their chemical composition without regard to the digestibility of the foods, and to the more or less prevalent idiosyncrasies of the public in connection with such foods. In an excellent article in The Times, Sir Wyndham Dunstan observes that “it has to be remembered that, however desirable the constituents of a given material may seem, in order to be of real value that material must be digestible— capable of assimilation within the body. In this matter of digestion people differ greatly and there must be latitude in the choice of food. While consumption in quantity of uncooked green and other vegetables is widely advocated, many are unable easily to digest some vegetables unless cooked, and not always then except in very moderate amount. Many other factors have to be taken into account in planning a common dietary. There are different tastes and preferences. The appeal a particular food makes to the individual and the appetite it stimulates are important points. The psychological factor plays a significant part and must be met by providing as wide a selection of palatable food as possible. These are a few truisms often overlooked.” With regard to the kind of bread we should eat and ought to be made to eat in war‐time, the writer observes that “there is unanimity in regarding a wholemeal bread (not always the same thing as “brown” bread) as that which should be generally eaten and readily procured. This is not at present the rule. Should it be made so? The constituents of wholemeal bread supply not only nourishment for the body but protection against ill‐health. Some of the more valuable constituents are absent from the white bread, so long the staple of this country, because they have been removed in the conversion of the wheat into white flour, which is now often further whitened and further deteriorated by a chemical bleaching agent. White bread is therefore a sophisticated and inferior food to which we have grown so accustomed that its use has become an ingrained habit. The obvious course in the circumstances, especially in war‐time, would be to compel the use of wholemeal bread and prohibit white bread. But, though such a course would be for the good of the nation, a sudden change of the kind, however beneficial, is bound to be inconvenient, if not distasteful, to many who are attached to white bread, and particularly to those who do not, or cannot, understand the need for change. There are people who say they can digest white bread more easily than “brown.” Thus it happens that the Ministry of Food, advised by numerous experts and confronted with numerous objectors, is apparently in favour of the evasive alternative of restoring artificially to white bread one at least of the valuable constituents it has lost in manufacture without impairing its whiteness. At first it was intended to do this by adding to white flour suitable quantities of two chemically prepared substances, one a vitamin and the other a calcium compound. Recently the synthetic vitamin only has been indicated as the proposed addition. This seems a clumsy and unnecessary concession to sentiment, involving considerable expenditure. It has been widely critised and regarded as “faking” bread. An eminent physician, Sir Ernest Graham Little, while condemning the proposal on general grounds, also questions its efficacy. Why first remove a natural constituent of wheat in making flour and then afterwards, at a cost, add to the flour this constituent artificially manufactured: He presents a convincing case for the use of wholemeal bread. With regard to the argument that some people dislike wholemeal bread and find it less easy to digest, it may be doubted whether many of them have eaten true wholemeal. “Brown” breads, including bread made with coarse ground wheat or bran and also several varieties of “brown” bread sold under largely advertised names, are almost everywhere procurable at higher prices than white bread. Fine wholemeal bread as well as flour is less easy to find. Large numbers of people eat very little bread, and it is therefore of small importance to them whether it is wholemeal or white. They consume far less than the three‐quarters of a pound a day included in Sir William Bragg's basal diet and make up for it with other foods which they can afford to buy. A really nutritious bread chiefly concerns the poorer classes, who eat much more bread than those better off. For the poor the substitution of wholemeal bread for white is a matter of far‐reaching importance. It has been stated that in many places wholemeal is dearer than white, but inquiries in the trade suggest that this is not as it should be, apart from “fancy” brown breads. As has been pointed out, the Ministry of Food, confronted with alternatives, apparently favour the introduction of “faked” white bread rather than the adoption of wholemeal. There is, however, a medium course. In this country we have come to recognise the “inevitability of gradualness,” and the medium course would meet present needs and might lead to the voluntary adoption of all that is desired.— It has been found that the admixture with fine ground wholemeal flour of about 10 per cent. of white flour makes a light coloured, very palatable, and digestible bread of good texture. Its nutritive value is very little less than that of full wholemeal bread; in fact a rather larger proportion of white flour would be permissible. The mixed flour is quite satisfactory for rolls, scones and cakes.” If an admixture of the kind suggested would overcome the prejudice against wholemeal bread and render it palatable to those people who dislike the ordinary wholemeal bread, there would seem to be a very strong case for adopting such a suggestion rather than first to remove a natural constituent of wheat and subsequently, at a cost, artificially add to the flour the constituent which has been removed in the manufacture of the flour.

In an interesting article, which recently appeared in The New Statesman, relating to the prevalence of bovine tuberculosis, the writer observes that whenever the question of tubercle in milk is raised, reassuring statements are promptly forthcoming from official sources, but apparently they are not always based upon sound knowledge. For example, the Minister of Agriculture stated in the House of Commons some months ago that the working of the Tuberculosis Order of 1925 showed that only about two per cent. of the cattle in England are affected. This statement is in all probability not only wrong, but wrong to an extent that would surprise any save those who are in touch with actual conditions. Reliable statistics tend to suggest that more than 30 per cent. of the cows in the British Islands are affected by the disease, the only exceptions to this proportion being in those herds which have been submitted regularly to the tuberculin test and from which reactors have been eliminated. The whole question is so important that no apology is needed for dealing with it here and setting out facts rather than theories. In 1924 a herd of 84 cows and 2 bulls belonging to a leading agriculturist was submitted to the tuberculin test; both bulls and 54 cows reacted. A year later, when the herd consisted of 87 cows and 2 bulls, 12 cows and 1 bull were tested for the first time. The bull and 11 cows reacted; of the remaining 75 cows and 1 bull only 7 cows reacted. In 1926 the herd consisted of 108 cows and 3 bulls; 11 cows were tested for the first time and 4 reacted. Of the remainder of the herd, consisting of 97 cows and 3 bulls, there were only 5 reactors, all cows. Many of the reactors in 1924–25–26 were slaughtered and tuberculosis was found to be present in every beast examined. There are at least four methods of testing: intradermal, ophthalmic, palpebral and subcutaneous, the subcutaneous being reliable under laboratory conditions for the first time only, because the maximum period of nonreaction to this test is not yet ascertained. It is well to remember that a tuberculous cow does not necessarily give tuberculous milk; in fact, little more than one per cent. of the cows that are afflicted with the disease have affected milk, and this is usually found where there is udder trouble. The tuberculin test is optional and at present owners are left to report suspected cases in their herds to the police. It follows in a great majority of cases that the cows they report are wasters, only fit for the knacker, who will pay 10s. to 15s. a piece for them. It is likely that a high percentage of cows in herds of standing, where the tuberculin test is not given regularly, would react to it. Under the Milk and Dairies Order of 1926, which came into operation in October of that year, sanitary authorities are required to keep registers of all persons carrying on the trade of dairykeeper or cowkeeper in their district, and all farms and other premises which are used as dairies; no man may carry on the trade of dairykeeper or cowkeeper unless he and his premises are registered. County Councils and County Borough Councils may order inspections, and a cowkeeper may not permit any cow to be removed from his premises after he has received notice that the Inspector is about to make a call. Further provisions for light, air and water made under the Order have been postponed for the benefit of the trade, but they will come into working not later than 1929. The powers of the Medical Officer of Health are considerable; if he is of opinion that anybody is suffering from an infectious disease caused by the consumption of milk supplied within the district from any registered premises, he may stop that supply until he is satisfied that there is no longer any trouble. There are in the Order many other clauses of interest to the consumer and the cowkeeper is obliged to take a large number of precautionary measures which will tend to increase rather than to diminish. Unfortunately the Milk and Dairies Act of the Ministry of Health and the Tuberculosis Order of the Ministry of Agriculture are not administered with uniformity. The local authorities up and down the country appear to vary the procedure as they think best. In these days when so great an effort is being made to promote increased consumption of milk, and when the food value of the pure article is admitted on nearly every hand, herds should be inspected regularly by a qualified veterinary surgeon, once a year at least, and certain of the present methods should be very carefully revised. To show the danger of the present procedure the following authenticated instances are interesting. Not long ago the London County Council, in accordance with the Milk and Dairies Act, took samples of milk from four distributors and caused it to be examined biologically. This examination took six weeks and in every case the milk was found to be tuberculous. The Medical Officer of the County from which the milk came was notified and he caused the herds in question to be examined and samples taken once more for biological examination. Tubercle being found, the case was handed over to the police to deal with under the Tuberculosis Order, and the Veterinary Inspector under the Contagious Diseases of Animals Act repeated the examination. In one of these four cases the London County Council notified the County Medical Officer in October, 1926, and the alleged offender among the herd was discovered by a process of elimination over a long period in April, 1927! On discovery the Veterinary Inspector condemned the beast and arrangements were being made for its slaughter when the owner produced a certificate to show that this particular cow was free from tuberculosis; it had been submitted to the tuberculin test and failed to react. A further sample was taken and the cow was pronounced healthy. In none of the four cases referred to was any cow giving tuberculous milk traced. It is not difficult to understand why this should be so. In these days, when many leading dairymen record their milk, some of them sell cows as soon as they are going out of profit and buy down‐calvers in order to keep the herd in full profit It follows that by the time the milk has been submitted to two or three biological examinations and three or four months have passed, the cow that has caused trouble may be infecting another herd. When we come to remember how closely the cows stand together in most cow houses, and how quickly, in the heated atmosphere of most of them, germs would spread, particularly in the winter, it is very easy to realise that the healthy may be infected by the sick and that many a cow may be tuberculous long before the owner has any idea that there is trouble. Something should be done to shorten procedure without rendering it ineffective, and the testing should be compulsory. At present an animal reported under the Tuberculosis Order and condemned is valued by agreement between the Local Authority and the owner of the animal, and if they fail to agree by a valuer appointed by the local authority and the owner, and the market value is assumed to be the price which might reasonably have been obtained from a purchaser in the open market who had no knowledge of any trouble other than he might have been supposed to have learned from inspection. If an animal, after being slaughtered, is found to be free from tubercle, the local authority must pay the market value plus 20s. If the animal was suffering from tuberculosis that was not in an advanced stage the local authority must pay a sum equal to three‐quarters of the market value, or 45s., whichever is the greater. If the animal was suffering from advanced tuberculosis, the compensation is one‐fourth of the market value, or 45s., whichever is the greater. This system of compensation is not found satisfactory. The owner may be honestly unaware of his cow's condition, he may even be disposed to do his best in the public interest, but when a man has any doubt as to whether he will get a fair price or not for his beast, he is extremely unlikely to submit to these examinations; he would prefer, unless the symptoms are obvious, to take the chance of selling in the open market. One of the difficulties of the position is to find the most suitable method of dealing with reactors, because the tuberculin test does not tell to what extent any animal is affected. But undoubtedly the present practice would be much improved if the control of diseases in cows were looked after by a department of the Ministry of Health, with a chief veterinary officer at its head who would be directly responsible to the Minister. All orders under the Contagious Diseases of Animals Act should be administered in the same fashion in all counties, i.e., by a veterinary officer and not by the police. Under the Dairies Acts veterinary inspection of all milk‐giving cows should be obligatory and not optional, and the full market value should be paid to owners whose cows are slaughtered under the Tuberculosis Order. The excessive delay and the duplication of procedure that is now so common should be avoided in some fashion that may be found practical by those who are best qualified to handle an extremely difficult situation. It is important that we should not deal too optimistically with the question of tuberculosis in cows. There is a big movement to increase the consumption of milk, yet there is ample evidence to lead us to believe that, outside the tested herds at least, one cow in three or four is tuberculous.

For maintaining the fortitude of both body and mind during war‐time, it is of prime importance that everyone should strive to do all that is possible to provide a sufficient amount of suitable food; for a well‐nourished body withstands infection and the effects of stress and strain just as a well‐built house resists the onslaughts of wind and rain.

Numerous problems have arisen in the application of freezing methods to the various types of food products. One problem is concerned with the determination of the direct effects of low temperatures upon the food itself and another problem is to determine the effects of low temperatures upon other factors which may in turn affect the quality of the food. We are especially interested in knowing the exact effects of freezing and other low temperatures upon the micro‐organisms associated with foods. Bacteria constitute the most significant group of micro‐organisms affecting the sanitation and keeping qualities of foods. Those bringing about the decomposition of food products, while they are many and vary greatly, depending upon the nature of the food, are chiefly organisms from the air, water and soil. The types of bacteria found in foods vary greatly in their action on the food and also in reaction or response to varying temperature conditions. The action of micro‐organisms on foods of high carbohydrate content results in fermentations, while the action of the micro‐organisms on foods of high protein content will result, chiefly, in putrefactive changes. The former type of change usually occurs at a more rapid rate, when conditions are favourable, but the latter change usually results in a more undesirable condition of the food. While certain types of bacteria grow best at temperatures well above human body temperatures and others even as low as the freezing point of water, a large majority of those found in foods and the ones normally responsible for the detrimental changes in foods, are active only between 50° and 100° F. It is this latter group which is most implicated in food spoilage and it is significant that this group will be most effectively suppressed by low temperatures. Bacteria are much less affected by low than by high temperatures. Cold alone does not kill most types of bacteria, but slows down their activities to such an extent that they multiply very slowly, if at all. Many bacteria will die off, however, when held at a temperature below that which permits growth and reproduction. Bacteria, generally speaking, will be more easily killed when frozen in pure water than when frozen in foods containing albuminous matter and fats. There are a few bacteria of the cold‐loving type, which may actually multiply and cause slow decomposition at temperatures of 0° C. or less, if substances in solution are present to depress the crystallising point of water. Cold not only retards the growth of bacteria by the direct physiological effect of slowing down the rate of metabolism, but also depresses bacterial activity through its effect on their water and food supplies. Bacteria cannot grow and multiply in a completely frozen or crystallised medium, since they are by nature aquatic and are unable to carry on their normal activities except in a liquid medium. There is no evidence that bacteria maintain a body temperature which would make water available from a completely frozen medium. Bacteria may only utilise food when it is in soluble form, and thus capable of diffusion through their semipermeable cell membranes. When the temperature is sufficiently low to cause the crystallisation of most of the water, the remaining constituents become relatively more concentrated and this will further suppress the activity of the bacterial cells by affecting their osmotic pressures. These effects are very similar to those of partial desiccation or drying. In the course of experimentation some very striking examples of bacterial resistance to low temperatures have been reported. Lactobacillus and aerobacter have been reported to survive in peas stored at −10° C. for two years; whilst bacteria of the genus Pseudomonas were reported to increase in numbers when stored at −4° C. In general it may be said that practically all pathogenic bacteria likely to be found in foods will die off rather rapidly at low temperatures. However, this should not be interpreted to mean that infected foods can be made safe by low temperatures alone. Among the disease producing bacteria transmitted through foods, those of special significance include the organisms and toxins of botulism, typhoid fever, the several organisms of food poisoning called ptomaine poisoning, belonging to the Salmonella group (Salmonella enteritidis, etc.), and various organisms causing infections of the general nature of dysenteries or summer complaints of infants and adults. Frozen foods present no greater threat of botulism than foods preserved by other methods, yet it has been shown that Clostridium botulinum spores may survive freezing at −16° C. for as long as 14 months. The vegetables when thawed become toxic in from three to six days. Experiments have shown that Clostridium botulinum in foods preserved by “quick freezing” and subsequent storage at temperatures below 10° C., show no toxin production for at least 30 days. The lower the temperature of storage the greater the protection against botulism. All foods in which Clostridium botulinum might be present, and which have not been thoroughly heated, should be refrigerated at or near the freezing point. All foods which may harbour the botulism organisms or toxins should be selected with special care, before they are frozen, and care should be taken to see that they are kept frozen until used by the customer. Frozen vegetables should be used immediately after thawing. Thawing and refreezing is always objectionable since such a practice leads to loss of quality, and since bacterial growth and activity may occur during the period of thawing. While the typhoid organisms (Eberthella typhosa) shows considerable variation in resistance to low temperatures, it has been shown that about 99 per cent. will be killed immediately by freezing. Temperatures below freezing apparently have little more effect than the freezing point temperature. Small numbers of the Salmonella and similar organisms of the food poisoning groups may survive in frozen foods for periods of several weeks. It has been shown, however, that no significant growth of activity of these organisms will occur if the foods are refrigerated at 5° C. (41° F.) or less. Moulds and yeasts are of relatively little importance in frozen foods, both from the standpoint of sanitation and food spoilage. While low temperatures will materially retard the rate of enzymatic changes within food products, there is evidence that such changes continue to take place in frozen foods, even considerably below the freezing point. These changes probably account, in part, for the fact that frozen foods once thawed, will decompose more rapidly than foods which have not been frozen.

LIBRARIES have come impressively into the public picture in the past year or two, and seldom with more effect than when Their Majesties the King and Queen opened the new Central Reference Library at Manchester on July 17th. In a time, which is nearly the end of a great depression, that the city which probably felt the depression more than any in the Kingdom should have proceeded with the building of a vast store‐house of learning is a fact of great social significance and a happy augury for libraries as a whole. His Majesty the King has been most felicitous in providing what we may call “slogans” for libraries. It will be remembered that in connection with the opening of the National Central Library, he suggested that it was a “University which all may join and which none need ever leave” —words which should be written in imperishable letters upon that library and be printed upon its stationery for ever. As Mr. J. D. Stewart said at the annual meeting of the National Central Library, it was a slogan which every public library would like to appropriate. At Manchester, His Majesty gave us another. He said: “To our urban population open libraries are as essential to health of mind, as open spaces to health of body.” This will be at the disposal of all of us for use. It is a wonderful thing that Manchester in these times has been able to provide a building costing £450,000 embodying all that is modern and all that is attractive in the design of libraries. The architect, Mr. Vincent Harris, and the successive librarians, Mr. Jast and Mr. Nowell, are to be congratulated upon the crown of their work.

1. The principal legal provisions relating to the composition and description of food and drugs (apart from provisions as to poisons and other special drugs) in force on the 1st January, 1927, are:—