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 upon the subject. They are as follows:—That the use of formaldehyde or formalin, or preparations thereof, in food or drinks, be absolutely prohibited, and that salicylic acid be not used in a greater proportion than one grain per pint in liquid food and one grain per pound in solid food, its presence in all cases to be declared. That the use of any preservatives or colouring matter whatever in milk offered for sale in the United Kingdom be constituted an offence under the Sale of Food and Drugs Act. That the only preservative which it shall be lawful to use in cream be boric acid, or mixtures of boric acid and borax, and in amount not exceeding 0·25% expressed as boric acid, the amount of such preservative to be notified by a label upon the vessel. That the only preservative permitted to be used in butter and margarine be boric acid, or mixtures of boric acid and borax, to be used in proportions not exceeding 0·5% expressed as boric acid. That in the case of all dietetic preparations intended for the use of invalids or infants, chemical preservatives of all kinds be prohibited.

As the most commonly used chemical preservative is boric acid, free or in the form of borax, which is extensively employed in butter, cream, ham, sausages, potted meats, cured fish, and sometimes in jams and preserved fruit, the arguments for and against its employment deserve more detailed attention. It cannot be looked upon in the light of common adulteration because, in any case, the quantity used is but an inconsiderable fraction, and the cost of it is generally greater than that of the food itself. It is not used to hide any traces of decomposition that may have taken place or to efface its effects. On the other hand, it cannot be said to be “required for the production or preparation” of the articles with which it is mixed, since a fraction at least of similar articles are made without preservative. It enables food to be kept from decomposition, but it also lessens the need for cleanliness and encourages neglect and slovenliness in factories. It has no taste, or only a very slight one, hence does not manifest itself to the consumer in the same way as does common salt, and cannot therefore be avoided by him should he desire to do so. Its preservative action, that is, its potency, is very slight in comparison with most other preservatives; its potential injuriousness to man must be proportionately small. It is practically without interference upon salivary, peptic or tryptic digestion, unless given in large quantities. Experiments made by F. W. Tunnicliffe and R. Rosenheim upon children showed that neither boric acid nor borax, administered in doses of from 15 to 23 grains per diem, exerted any influence upon proteid metabolism or upon the assimilation of phosphatized materials. The fat assimilation was, if anything, improved, and the body weight increased, and the general health and well-being was in no way affected. On the other hand, evidence was adduced that in some cases digestive disturbances, after continuous administration of from 15 to 40 grains, were observable, nausea and vomiting in some, and skin irritation, in one case resulting in complete baldness, in others.

Although it is in most cases very difficult to trace any gastric disturbance to any particular article of food or one of its ingredients, so as to exclude all other possible causes of disturbance, a fairly good case has been made out by a number of medical practitioners against boracic acid, taken in an ordinary diet and not for experimental purposes. The most exhaustive investigation which has as yet been made was carried out by Dr H. W. Wiley, chief chemist to the United States department of agriculture. A large number of young men who had offered themselves as subjects for the investigations, were boarded as a special “hygienic table,” but otherwise continued their usual vocations during the whole period of the experiment. They were placed upon their honour to observe the rules and regulations prepared by the department and to use no other food or drink than that provided, water excepted, and any water consumed away from the hygienic table was to be measured and reported. They were to continue their regular habits and not to indulge in any excessive amount of labour or exercise. Weight, temperature and pulse rate were continuously recorded. The periods during which the subjects of the experiment were kept under observation varied from thirty to seventy days, periods of rest being given during which they were permitted to eat moderately at tables other than the experimental one. There was a good and ample diet. The observations were divided into three periods: the fore period, the preservative period and the after period, during the whole of which time the rations of each member were weighed or measured and the excreta collected. Before the “fore” period was commenced a note was made of the quantities of food voluntarily consumed by each of the candidates, and from these the proper amount necessary in each case to maintain a comparatively constant body weight was calculated. When a suitable result was thus arrived at, the same quantity of food was given daily during the “preservative” and “after” periods. The preservative was given in the forms of borax and of boric acid, at first mixed with butter, but subsequently in gelatine capsules. This was found to be necessary from the fact that when the preservative was mixed with the food and concealed in it some of the members of the table evinced dislike of the food with which it was supposed to be incorporated; those who thought that the preservative was in the butter were disposed to find the butter unpalatable, and the same was true with those who thought it might be in the milk or coffee, while, when the preservative was given openly, much less disturbance was created. The preservative was given at first in small doses such as might be consumed in commercial food that had been preserved with borax; gradually the quantities were increased in order to reach the limit of toleration for each individual. All food was weighed, measured and analysed, the same being the case with the excreta. The blood was examined periodically as regards colouring matter and number of corpuscles. Everything was done to keep up the general health of the members and to do away with all unfavourable mental influences due to the circumstances. During the time of the experiment analyses were made of 2550 food samples and 1175 samples each of urine and faeces. The general results were as follows: there was no tendency to excite diarrhoea, and the nitrogen-metabolism was but very little influenced, if anything being slightly decreased. As regards phosphorus the combined results of all observations indicated that the preservative increased the excretion of phosphorus to a small extent, from 97·3% in the “fore” period, to 103·1 in the “preservative” period. The metabolism of fat was uninfluenced; there was an increase of the solid matters in the faeces and a decrease of those in the urine, from which Dr Wiley concluded that the preservatives interfered with the process of digestion and absorption. No influence was exerted on the corpuscles and the haemoglobin of the blood. The effect of boracic acid and borax on the general health varied with the amount administered, quantities not exceeding half a gramme (7 grains) of boracic acid, or its equivalent of borax, producing no immediate effects, but the long-continued administration of such small doses seemed to produce the same results as the use of large doses over a shorter period. There was a tendency to diminish the appetite and to produce a feeling of fulness and uneasiness in the stomach and sometimes actual nausea, also one of fulness in the head manifested as a dull headache which disappeared when the preservative was dropped. The continued administration of large doses, 60 to 75 grains per day, resulted in most cases in loss of appetite, inability to perform work of any kind and general unfitness. In most cases 45 grains per day could be taken for some time, but gradually injurious effects were observed. In some cases 30 and even 15 grains per day appeared to cause illness, but it is acknowledged that these persons may have been suffering from influenza. The administration of 7·5 grains was declared by Dr Wiley to be too much for the normal man to receive regularly, although for a limited period there might be no danger to health. Dr Wiley concludes his report: “It appears, therefore, that both boric acid and borax, when continuously administered in small doses for a long period or when given in large quantities for a short period, create disturbance of appetite, of digestion and of health.”