Chapter 7

Meat Extracts.--Justus von Liebig, the great German chemist, was the first to attempt to make these on the commercial scale. He described a method in 1847, and this not proving satisfactory, another one in 1865. He stated that the only practicable plan on a manufacturing scale, was to treat the chopped flesh with eight to ten times its weight of water, which was to be raised to 180° F. In another passage he says it is to be boiled for half-an-hour. After straining from all the undissolved meat fibre, etc., and carefully cleansing from all fat, the decoction is to be evaporated to a soft extract; such a preparation is practically free from albumin, gelatin and fat; all the nutritive principles except the saline matter having been extracted. Liebig states that 34 pounds of meat are required to produce 1 pound of extract. In 1872, he wrote "neither tea nor extract of meat are nutritive in the ordinary sense," and he went on to speak of their medicinal properties. Druit, in 1861, in describing the effect of a liquid preparation of meat, states that it exerted a rapid and stimulating action on the brain, and he proposed it as an auxiliary and partial substitute for brandy, in all case of great exhaustion or weakness attended with cerebral depression or despondency. In like manner, a feast of animal food in savages, whose customary diet was almost exclusively vegetable, has been described by travellers as producing great excitement and stimulation similar to that of intoxicating spirits. Similar effects have been observed from a copious employment of Liebig's extract. Voit asserts, from the results of his experiments, that extract of meat is practically useless as a food, and other authorities are quite of the same opinion, although they may value it as a stimulant and drug. _The Extra Pharmacopæia_, 1901, states that "Liebig's Extract or Lemco consists of creatin, creatinin, globulin and urea, with organic potash and other salts. It has been much over-estimated as a food either for invalids or healthy persons; still it is often valuable as a flavouring to add to soups, beef-tea, etc., and it is a nerve food allied to tea." Meat extracts stimulate the action of the heart and the digestive processes, but as in the case of other stimulants there is a succeeding period of depression. The _British Medical Journal_ says that the widespread belief in the universal suitability of concentrated beef-tea is frequently responsible for increasing the patient's discomfort, and is even capable in conditions of kidney inefficiency, of producing positive harm. Some of the meat bases, the leucomaines, have been found to possess marked poisonous effects on the body. The manfacturers of meat extracts continue to mislead the public by absurdly false statements of the value of their products. They assert that their extracts contain the nutritive matter of 30, 40 or 50 times their weight of fresh meat, or that one or two meat-lozenges are sufficient for a meal. One company, asserts by direct statement, or imply by pictorial advertisement, that the nutritive matter in an ox can be concentrated into the bulk of a bottle of extract; and another company that a tea-cup full is equivalent in food value to an ox. Professor Halliburton writes: "Instead of an ox in a tea-cup, the ox's urine in a tea-cup would be much nearer the fact, for the meat extract consists largely of products on the way to urea, which more nearly resemble in constitution the urine than they do the flesh of the ox." Professor Robert Bartholow has also stated that the chemical composition of beef-tea closely resembles urine, and is more an excrementitious substance than a food. Those whose business it is to make a pure meat-broth, for the purpose of preparing therefrom a nutrient for experimenting with bacteria, cannot fail to recognise its similarity both in odour and colour to urine. Little consideration is needful to show the untruthfulness and the absurdity of the statements made by manufacturers as to the food value of these extracts. Fresh lean beef contains about 25 per cent. of solid nutriment and 75 per cent. of water. If lean beef be desiccated, one pound will be reduced to four ounces of perfectly dry substance; this will consist of about 80 per cent. of proteid matter and nearly 20 per cent. of fat including a little saline matter and the extractives. This is as far as it is possible to concentrate the beef. If it were possible to remove, without interfering with the nutritious constituents, the membraneous matter, the creatin, creatinine and purin bodies, we should reduce it to a little less than four ounces. It is very remarkable that the most nutritious matter of the beef, the muscle substance or proteid and the fat, are rejected in making Liebig's extract, whilst the effete or waste products are retained. In Bovril and some other preparations, some meat fibre has been added with the object of imparting a definite food value. Hence in some advertisements, now withdrawn, it was alleged that the preparations were immensely superior in nutritive value to ordinary meat extracts. The Bovril Company extensively circulated the following:--"It is hard for ladies to realise that the beef tea they make at home from the choicest fresh beef contains absolutely no nourishment and is nothing more than a slight stimulant. It is so, however, and many a patient has been starved on beef tea, whether made from fresh beef or from the meat extracts that are sold to the public. From these Bovril differs so much that one ounce of its nutritious constituents contains more real and direct nourishment than fifty ounces of ordinary meat extract." If analyses of meat extracts are referred to, it will be seen that the principal part of Bovril is the meat bases and other things common to all such extracts, and which the Company in their circular so emphatically condemn. If the meat fibre, which is the principal, if not the sole difference, is the only nourishing constituent, it is difficult to see the advantage over ordinary beef, which can be procured at a very small proportionate cost. Concerning this added meat fibre, C.A. Mitchell, in "Flesh Foods," writes: "As this amounts to at most some 8 or 10 per cent., it is obvious that a large quantity of the substance would be required to obtain as much unaltered proteid as is contained in an egg. On the other hand, it has been pointed out that there is nothing to show that flesh powder suspended in meat extract is more digestible than ordinary flesh in the same fine state of division, whilst the amount of flesh bases, the principal stimulating agents, is correspondingly reduced." Concerning added albumin and meat fibre, A.H. Allen, in "Commercial Organic Analysis," vol. iv., writes: "The amount of these constituents present in such a quantity of meat extract as is usually, or could be, taken at a time, is too insignificant to give it any appreciable value as nutriment." Notwithstanding such statements by analysts and others, Bovril is advertised to contain "the entire nourishment of prime ox-beef." The great extent of the extract of meat trade is shown by a circular issued by the Lemco and Oxo Company. They give the number of their cattle killed since 1865 as 5,550,000; stock of cattle 160,000; employees in works, farms and branches, 3,200. This is only one out of many such companies. It is a sad thing that myriads of animals should be slaughtered with all the horrible and brutalising surroundings of the slaughter-house to such a purpose--the nutritious matter being nearly all wasted. Reliance on these extracts is responsible for much sickness and death. Instead of their preventing colds, influenza, and other complaints as is professed, they predispose to them by overloading the body with waste products, taxing the excretory organs and reducing the vitality. The following analyses of meat extracts are by Otto Hehner:--

Gela- Albu- Meat Water. Fat. tin. min. Fibre.

Liebig Co.'s Extractum Carnis 15.26 0.34 5.18 -- 2.12 Armour's Extract of Meat 15.97 0.21 3.31 -- -- Brand & Co.'s Extractum Carnis 17.85 0.38 4.56 -- 1.81 Brand & Co.'s Meat Juice 55.48 0.10 0.69 1.00 -- Brand & Co.'s Essence of Beef 89.68 0.06 5.12 -- -- Valentine's Meat juice 55.53 0.10 0.75 0.25 -- Bovril Company's Fluid Beef 28.34 1.02 3.81 -- 5.37 Bovril for Invalids 24.34 1.07 4.56 -- 5.87

Albu- Pep- Meat moses. tones. Bases. Ash. Liebig Co.'s Extractum Carnis 2.01 8.06 39.32 23.51 Armour's Extract of Meat 1.75 5.13 41.12 29.36 Brand & Co.'s Extractum Carnis 4.19 10.16 38.90 18.80 Brand & Co.'s Meat Juice 1.06 2.50 12.50 11.06 Brand & Co.'s Essence of Beef 0.19 0.57 3.43 1.00 Valentine's Meat juice 2.00 2.87 12.48 12.01 Bovril Company's Fluid Beef 8.38 13.18 19.38 17.67 Bovril for Invalids 5.56 6.44 34.07 16.50

Some of the "Liebig's Extract of Meat" so called, contains yeast extract; some even, is almost entirely, if not altogether made from yeast. The latter can be manufactured at a very low cost from brewers' and distillers' waste products, and there is a strong incentive for unscrupulous dealers to substitute it secretly. Artificial meat extracts prepared from yeast have the appearance and taste of meat extracts, but some, at least, have a considerably sharper flavour. In one method of manufacture common salt is added, and this renders it unfit for use in more than very small quantities as a flavouring. J. Graff has made analyses of ten yeast extracts, and contrasted them with meat extracts (see _Analyst_ 1904, page 194), and says, "It will be seen that the chemical composition of yeast extract does not greatly differ from that of meat extract." Yeast extracts contain purin bodies, and are probably equally as injurious as meat extracts. Such strong and rank flavours (the odour is suggestive to us of putrefaction) should be discouraged by those who would cultivate a refined taste in food.

Flesh Bases and Waste Products.--As the result of destructive metamorphosis or the wearing out of the body, there remain certain waste products which have to be expelled as soon as is possible. Their retention and accumulation would soon produce death. A part is expelled by the lungs as carbon-dioxide, or as it is generally though less correctly termed, carbonic acid. Upon the breaking down of the complex proteid and other nitrogenous matter, the nitrogen is left in comparatively simple combinations. These effete nitrogen compounds are commonly termed flesh bases or nitrogenous extractives. They exist in small quantity in flesh meat, but are concentrated and conserved in the making of beef-tea or beef-extract. The spleen, lymphatic and other glands, and especially the liver, break these down into still simpler compounds, so that the kidneys may readily separate them from the blood, that they may pass out of the body. By far the largest part of this waste nitrogen is expelled from the bodies of men and many other mammals in the form of urea. Pure urea is an odourless transparent crystalline substance, of cooling saline taste like nitre. It is soluble in an equal volume of water, and is expelled from the body with great ease. In the herbivora the nitrogenous waste takes the form of another body called hippuric acid. The nearly solid light-coloured urinary excretion of birds and serpents consists of urates; this is uric acid in combination with alkalies. In man, in addition to the urea excreted, there is also a little hippuric and uric acid or compounds of these. Uric acid is a transparent colourless crystalline body almost insoluble in water but soluble as urates in the presence of alkalies. As deposited from urine it is of a dull red sand-like appearance, as it has a great affinity for any colouring matter that is present.

It is only possible to make a brief reference to the chief organic bases. The xanthine bases are closely related to uric acid. Some of these occur in small quantity in the urine and animal tissues, others, such as caffeine, occur in plants. Creatine is a constant constituent of muscle substance. In fowl's flesh there is said to be 0.32 per cent., in cod-fish 0.17 per cent., and in beef 0.07 per cent. Creatinine is produced from creatine with great facility; it exists in urine. Both creatine and creatinine are readily soluble in water. A series of bases, closely allied to creatinine have been isolated from the flesh of large animals by A. Gautier; they are known as Gautier's flesh bases. When administered to animals, these act more or less powerfully on the nerve centres, inducing sleep and in some cases causing vomiting and purging in a manner similar to the alkaloids of snake venom, but less powerfully than the ptomaines. These bases are formed during life as a result of normal vital processes and are termed leucomaines.

Another class of bases of an alkaloidal nature, are termed ptomaines; these differ from the leucomaines, being produced by putrefactive or bacterial agency from dead flesh. The poisoning which has occasionally resulted from the eating of sausages, pork-pies, tinned meats, etc., is due to their having contained ptomaines.

Such quantities of waste products as are produced in the healthy body are excreted with ease, but it is otherwise in certain diseases. Either specially noxious substances are produced, or the usual substances are in excessive quantity and not eliminated with sufficient rapidity; in consequence the body is poisoned. Those who eat largely of flesh, introduce into their system the excretory matter contained therein, which super-added to the excretory matter resulting from the vital processes of the body puts an unusual and unnatural strain upon the liver and kidneys. It has been observed, that the eating of the flesh of some trapped animals has produced severe symptoms of poisoning. The pain and horror of having a limb bleeding and mangled in a most cruel steel trap, the struggles which only add to the misery, slowly being done to death during hours or even days of torture, has produced in their bodies virulent poisons. Leucomaine poisons have also been produced by the violent and prolonged exertions of an animal, fleeing from its pursuers, until its strength was completely spent. Cases are also known, where a mother nursing her infant, has given way to violent anger or other emotion, and the child at the breast has been made violently ill. We must not expect the flesh of any hunted or terrified animals to be wholesome. Animals brought in cattle ships across the Atlantic, suffer acutely. After rough weather they will often arrive in a maimed condition, some being dead. To this is added the terror and cruelty to which they are subjected whilst driven by callous drovers, often through a crowded city, to the slaughter house to which they have an instinctive dread. It is only to be expected that the dead flesh from such animals, should contain an unusually large quantity of the more poisonous flesh bases.

Purin Bodies.--The term purin has been applied to all bodies containing the nucleus C_{5}N_{4}. It comprises the xanthine group and the uric acid group of bodies. The principal purins are hypoxanthin, xanthin, uric acid, guanin, adenin, caffeine and theobromine. Purins in the body may either result from the wear and tear of certain cell contents, when they are called endogenous purins; or they are introduced in the food, when they are distinguished as exogenous purins. These purins are waste products and are readily converted into uric acid. The production of some uric acid by tissue change is, of course, unavoidable; but that resulting from the purins in food is under control.

An excess of uric acid is commonly associated with gout and similar diseases. The morbid phenomena of gout are chiefly manifested in the joints and surrounding tissues. The articular cartilages become swollen, with ensuing great pain. There is an accumulation of mortar like matter about the joints. This is calcium urate (not sodium urate as is generally stated). These nodular concretions are called tophi or chalkstones.

Very many are the hypotheses which have been propounded on the cause of gout and the part played by uric acid; many have had to be discarded or greatly modified. Though much light has recently been thrown on the subject, there remains much that is obscure. The subject is one which is surrounded with great difficulties, and would not be suitable for discussion here, were it not for the following reason: Certain views on uric acid as the cause of gout and several other diseases, are at the present time being pushed to the extreme in some health journals and pamphlets. Unfortunately many of the writers have very little knowledge, either of chemistry or physiology, and treat the question as though it were a simple one that had been quite settled. Our purpose is to clear the ground to some extent, for a better understanding of its fundamentals, and to warn against dogmatism. Our remarks, however, must be brief. It is undeniable that great eaters of meat, especially if they also take liberally of alcoholic drinks, are prone to diseases of the liver and kidneys, about or soon after the time of middle life. Flesh meat contains relatively large quantities of purins. Purins are metabolised in the body to uric acid, about half of the uric acid produced in the body disappears as such, being disintegrated, whilst the other half remains to be excreted by the kidneys.

One view is that whilst the organs of the body can readily dispose of its endogenous uric acid, or that produced by its own tissue change, together with the small amount of uric acid derived from most foods, the organs are strained by the larger quantity introduced in flesh-food or any other food rich in purins: that there is an accumulation in the system of some of this uric acid. Vegetable foods tend to keep the blood alkaline, flesh possesses less of this property; alkalinity of the blood is thought to be favourable to the elimination of uric acid, whilst anything of an acid nature acts contrarily. Dr. Alexander Haig writes "I consider that every man who eats what is called ordinary diet with butcher's meat twice a day, and also drinks acid wine or beer, will, by the time he is 50, have accumulated 300 to 400 grains of uric acid in his tissues, and possibly much more; and about this time, owing to the large amount of uric acid in his body, he will probably be subject to attacks of some form of gout or chronic rheumatism." Dr. Haig ascribes to the presence of uric acid in the system, not only gout and rheumatism, but epilepsy, hysteria, mental and bodily depression, diseases of the liver, kidneys, brain, etc.

The opinion of the majority of eminent medical men, during recent years, is that uric acid is not a cause, but a symptom of gout, that uric acid is not an irritant to the tissues, and that it is readily excreted in the healthy subject. Some of the reasons for this latter and against the previously stated hypothesis, are as follows:--Birds very rarely suffer from gout--the nodular concretions, sometimes found about their joints and which have been ascribed to gout, are of tuberculous origin--yet their blood contains more uric acid than that of man, and the solid matter of their excretion is mainly urates. If uric acid caused gout we should expect the disease to be common in birds. It is a remarkable fact that the waste nitrogen should be excreted in the form of uric acid or urates from such widely differing classes of animals as birds and serpents. Birds have a higher body temperature than man, they are very rapid in their movements and consume a large amount of food proportionate to their weight. They live, as it were, at high pressure. Serpents, on the other hand, have a low body temperature, they are lethargic and can live a long while without food. There is no obvious reason why some animals excrete urea and others uric acid. As uric acid is a satisfactory and unirritating form in which waste nitrogen is expelled from the body of the active alert bird, as well as from the slow moving reptile, it is surprising if a very much smaller quantity acts as a poison in man. Many physicians are convinced that uric acid is absolutely unirritating. Uratic deposits may occur to an enormous extent in gouty persons without the occurrence of any pain or paroxysms. Urates have been injected in large amounts into the bodies of animals as well as administered in their food with no toxic result whatever, or more than purely local irritation. The most careful investigations upon the excretions of persons suffering from gouty complaints, have failed to show uric acid in the excretions in excess of that in normal individuals, except during the later stage of an acute attack. There is an excess of uric acid in the blood of gouty subjects; some eminent medical men say it is in the highest degree probable, that this excess is not due to over production or deficient destruction, but to defective excretion by the kidneys. The excess may arise from failure of the uric acid to enter into combination with a suitable substance in the blood, which assists its passage through the kidneys. Under the head of gout are classed a number of unrelated disturbances in the gastro-intestinal tract and nutritive organs, whose sole bond of union is that they are accompanied by an excess of urates, and in well developed cases by deposits in the tissues. This is why there are so many different causes, curative treatments, theories, contradictions and vagaries in gout. There are good reasons for believing that uric acid is not in the free state in the body. In the urine it is in combination with alkalies as urates, perhaps also with some organic body. It has been shown that the blood of the gouty is not saturated with uric acid, but can take up more, and that the alkalinity of the blood is not diminished. The excess over the normal is in many cases small; it is said to be absent in some persons, and rarely, if ever reaches the quantity found in leukaemia. Leukaemia is a disease marked by an excessive and permanent increase in the white blood corpuscles and consequent progressive anæmia. Neither does the uric acid of gout reach the quantity produced in persons whilst being fed with thymus gland (sweetbread), for medical purposes. In neither of these cases are any of the symptoms of gout present. In the urine of children, it is not unusual to find a copious precipitate of urates, yet without any observed effect on them.