Malic acid

“ It sublimes to some extent at about 200° C., being partially converted into maleic anhydride and water, the reaction becoming practically quantitative if dehydrating agents be used. Reducing agents (zinc and caustic alkali, hydriodic acid, sodium amalgam, &c.) convert it into succinic acid. Bromine converts it into dibromsuccinic acid. Potassium permanganate oxidizes it to racemic acid (A. Kekulé and R. Anschutz, Ber., 1881, 14, p. 713) . By long-continued heating with caustic soda at 100° C. it is converted into inactive malic acid.
Maleic acid is obtained by distilling malic or fumaric acids ”

“ Nay, an obvious mode of correcting excessive acidity, produced by too much tartaric acid, is to add tartaric acid, and then to treat the mixture with oxide of lead. Fourcroy farther thinks, that the malic acid possesses the same solvent power as the acetic over tartrate of lead, and that its presence may therefore be the reason why some tart wines, which do not contain the acetic acid, become nevertheless impregnated with the poison. The solvent power of acetic acid is increased by the 422presence of other vegetable principles in the wine. ”

“ MALIC ACID (Hydroxyethylene Succinic Acid) , C4H6O5, an organic acid found abundantly in the juices of many plants, particularly in mountain-ash berries, in unripe apples and in grapes. The acid potassium salt is also found in the leaves and stalks of rhubarb. Since the acid contains an asymmetric carbon atom, it can exist in three forms, a dextro-rotatory, a laevo-rotatory and an inactive form; the acid obtained in the various synthetical processes is the inactive form. It may be prepared by heating racemic acid (see Tartaric Acid) with fuming hydriodic acid ”

“ The presence of Oxalic Acid 256may be inferred, if the solution, when added to that of sulphate of lime, produce a precipitate. Malic acid has the power of precipitating silver, mercury, and lead, from their solutions in nitric acid, but no doubt or difficulty can arise from this circumstance, for the fact of its forming a soluble salt with lime will prevent every chance of accidental intrusion, and its price at once secures us against its fraudulent introduction ”

“ The tartrate of lead is very sparingly soluble in an excess of its acid, so that a sweet taste cannot be communicated by it to a fluid acidulated with tartaric acid. Malic acid, according to MM. Chevallier and Ollivier, acts so quickly as a solvent, that if a solution be kept in a lead vessel for three hours, the metal may be detected in the fluid by any of its ordinary tests. [1260]
The acids act with greater rapidity on the protoxide of lead than on the metal; and the presence of air is of course not required to enable them to effect its solution. ”

“ The fresh juice of the herb contains malic acid in a free state, various salts, and a red colouring matter; also glucose, and a peculiar crystallisable acid. Cattle of the female gender are said to have their copulative instincts excited by eating even a small quantity of the plant. Throughout Europe it has long been esteemed a remedy of repute for chronic bronchitis and asthma; and more recently, in the hands of homoeopathic practitioners, it has acquired a fame for specifically curing whooping cough in its spasmodic stages, after the first feverishness of this malady has become subdued. ”

“ The acid is secreted by numerous one-celled cylindrical hairs. It consists of a mixture of oxalic, acetic, and malic acids, and, being very disagreeable to slugs and snails, constitutes an efficacious protection against their ravages. A simple contact of its tentacles or teguments with the secretory hairs is enough to cause the animal to draw back and go somewhere else to indulge its cravings. But if the leaves are washed, and the hairs cleansed of the acid secretion, they will be eaten at once.
Many plants are furnished with strong and pungent ethereal oils or similar substances. ”

“ Thus the male cells of ferns are attracted not only by the malic acid secreted naturally by the archegonia, but by synthetically prepared malic acid, whilst the male cells of mosses are attracted either by the natural acid of the female cells or by acid prepared from cane sugar. ”

“ From the liquor remaining after the first cristallization of the oxalic acid we may obtain malic acid by refrigeration: This acid is more oxygenated than the oxalic; and, by a further oxygenation, the sugar is convertible into acetous acid, or vinegar.
The oxalic acid, combined with a small quantity of soda or potash, has the property, like the tartarous acid, of entering into a number of combinations without suffering decomposition: These combinations form triple salts, or neutral salts with double bases, which ought to have proper names. ”

“ Perry contains about one per cent. alcohol over cider, and a slightly larger proportion of malic acid, so that it is rather more stimulating, and somewhat better calculated to produce the healthful effects of vegetable acids in the economy. How eminently beneficial fruits of such sort are when ripe and sound, even to persons out of health, is but little understood, though happily the British public is growing wiser to-day in this respect. ”

“ At the same time, it is a remedy which should be tried in case of failure with others.
The usual astringents, mineral and vegetable, of known efficacy in the treatment of hemorrhagic conditions, should be used alone or in conjunction with the specific anti-malarial treatment after the latter has been found of itself insufficient. To this class of remedies belong the mineral acids, persulphate of iron, acetate of lead, alum, gallic acid, catechu, kino, the astringent natural mineral waters, etc.
Rest is certainly an important adjuvant in the treatment of this form of malarial disease. ”

“ The same cause will always produce the same results. When vegetable matters rise from a large surface of earth or mud (as from the newly-drained forty thousand acres of the lake of Haarlem) , there are no plants there to inhale the carbonic acid, and to give out oxygen; but those seeds being rotten or in a state of ferment, the oxygen for the decomposition is drawn from the atmosphere alone, and human beings who breathe this malaria have fever ”

“ It is a most important synthetic reagent; with sodium or sodium ethylate it forms sodio-malonic ester, which reacts readily with alkyl halides, forming alkyl malonic esters, which are again capable of forming sodium derivatives, that by further treatment with alkyl halides yield the di-alkyl malonic esters. These esters are readily hydrolysed and yield the mono- and di-alkyl malonic acids which, on heating, are readily decomposed, with evolution of carbon dioxide and the formation of mono- and di-alkyl acetic acids. ”

“ In a short time after the event, animal matters lose their cohesion; they are dissipated into the air, leaving only the mineral elements they had derived from the soil. The change commences immediately after death: with the aid of moisture and exposure to the air, the bodies of animals, as well as plants, undergo changes, the last of which are30 the conversion of their carbonic acid and of their hydrogen into water, of their nitrogen into ammonia, of their sulphur into sulphuric acid. ”

“ If the stomach is examined immediately after death, little corrosion will be found, compared with what is seen if the inspection be delayed a day or two. [401]
Such are the effects of the concentrated acid. When considerably diluted, the phenomena are totally different. When dissolved in twenty parts of water, oxalic acid, like the mineral acids in the same circumstances, cease to corrode; nay it hardly even irritates. But, unlike them, it continues a deadly poison; for it causes death by acting indirectly on the brain, spine, and heart. The symptoms then induced vary with the dose. ”

“ Emetics and Purgatives, to get rid of the poison; and chemical antidotes, to neutralize it or render it insoluble while in the stomach. With this last object, acids are given in alkaline, and alkalies in acid poisoning. The soluble salts of Lead may be precipitated and rendered insoluble by sulphuric acid or sulphates. Those of Mercury, Copper, and Zinc, by albumen. Tannic acid precipitates the vegetable alkaloids. There are some other special antidotes of the same kind. ”

“ The external application of oxalic acid does not appear to cause illness; workmen engaged in trades requiring the constant use of the acid often have the nails white, opaque, and brittle; but no direct injury to health is on record.
A large dose of either causes a local and a remote effect; the local is very similar to that already described as belonging to the mineral acids, i.e., more or less destructive of the mucous membranes with which the acid comes in contact. The remote effects may only be developed after a little; they consist essentially of a profound influence on the nervous system. ”

“ Ten or fifteen grains of the sulphate are often given three times a day for this latter purpose, and smaller doses of the much more efficacious acid hydrochloride will be found to convey even more certain immunity. In treating malaria (including ague, remit tent fever, intermittent fever, and all its other forms) with this drug certain important facts are to be observed. Quinine administered by the mouth or by any other means will soon enter the blood, and will then kill the haematozoon malariae, whether it be free in the blood-plasma, in the leukocytes or in the red blood corpuscles. ”

“ DIVISION I.—CHEMICAL CORROSIVE POISONS THE MINERAL ACIDS
General Characters.—The mineral acids have no remote effects on the system; their action is purely local. They are seldom used for the purpose of homicide, except in the case of young children. By suicides they are more frequently employed.
The Symptoms common to the action of these acids supervene immediately the acid is swallowed, and consist in a sensation of burning in the mouth and gullet. ”

“ It is proper to observe, that acids act upon Metalline Substances, in one respect, just as they do upon alkalis and absorbent earths: for an acid cannot take up above such a certain proportion thereof as is sufficient to saturate it, to destroy several of its properties, and weaken others. For example, when an acid is combined with a metal to the point of saturation, it loses its taste, does not turn the blue colour of a vegetable red, and its affinity with water is considerably impaired. ”

“ It must be always borne in mind that, with regard to statistics generally, the term “carbolic acid” is not used by coroners, juries, or medical men, in a strictly chemical sense, the term being made to include disinfecting fluids which are almost wholly composed of the cresols, and contain scarcely any phenol. In this article, with regard to symptoms and pathological appearances, it is only occasionally possible to state whether the pure medicinal crystalline phenol or a mixture of tar-acids was the cause of poisoning. ”

“ M. Chevallier, in a paper on the antidotes for the mineral acids, quotes five cases of poisoning with sulphuric acid and two with nitric acid, where life seems to have been saved by the speedy and free administration of magnesia, although in some cases so large a quantity as two ounces of the poison had been swallowed. [299] —A solution of soap is another antidote of no small value. While the antidote is in preparation, the acid should be diluted by the free use of any mild fluid, such as milk or oleaginous matters.—The alkaline bicarbonates are also excellent antidotes ”

“ The decomposition of the rotting of the woody fibre is attended with this peculiarity—when in contact with the air, it converts the oxygen into an equal volume of carbonic acid; so soon as the supply of the oxygen ceases the rottenness stops. Now remove this carbonic acid, and add a fresh supply of oxygen, and the rotting commences, and carbonic acid reappears. The presence of water is essential to this change; the substances called antiseptic arrest it at once. Now the woody fibre in this condition of slow combustion or rottenness is precisely what we call humus or ulmine. ”

“ We know nothing precisely about the nature of the cultivation which should be adopted in order to produce in a given species of malarious soil a final modification of its physical conditions and chemical composition which shall render it incapable of producing the poisonous ferment. At present we are feeling our way, with the result that often we obtain useful results by means of high cultivation, and as often not." Dr. Tommasi-Crudelli recommends arsenious acid and the alkaline arseniates as the most efficient protective agents against malaria. ”

“ A comparative survey of the anatomy of the vertebrates shows that as a general rule the longer the intestine the shorter the life. He does not advocate its extirpation by surgery or its disinfection by chemicals, but he would crowd out its wild and poisonous flora by harmless cultivated species. Among the friendly microbes he regards the lactic acid bacilli as most useful for this purpose. These act upon milk or fruit sugar, converting it into lactic acid, which is destructive to most other microbes, including some of the most dangerous. ”

“ Acetic acid is a strong corrosive poison; if taken internally, causes vomiting, with intense pain, followed by convulsions and fatal coma. If the acid remains in the stomach for some time it may eat its way through the stomach wall. In cases of poisoning by acetic acid, milk or flour and water should be freely given and vomiting produced. Weak alkalies should also be given as antidotes. Glacial acetic acid is used as an application to cancer of the skin, ulcers, warts, growths in the nose, ringworm, lupus (Jacob's Ulcer) and other ulcerous growths. ”