Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 44

_Prop., &c._ Pale rose-coloured crystals of the formulae MnSO_{4}, 7Aq.; MnSO_{4}, 5Aq.; or MnSO_{4}, 4Aq.; according to the method of crystallising, furnishing a solution of a rich amethystine colour. With sulphate of pota.s.sa it forms a double salt ('manganese alum').--_Dose._ As an alterative and tonic, 5 to 10 gr.; as a cholagogue cathartic, 1 to 2 dr., dissolved in water, either alone or combined with infusion of senna.

According to Ure, its action is prompt and soon over; 1 dr. of it occasions, after the lapse of an hour or so, one or more liquid bilious stools. In large doses it occasions vomiting, and in excessive doses it destroys life by its caustic action on the stomach. (Dr G. C.

Mitscherlich.) It has been administered with manifest advantage in torpor of the liver, gout, jaundice, syphilis, and certain skin diseases; and, combined with iron, in anaemia, chlorosis, rickets, &c.

=Manganous Tar'trate.= MnC_{4}H_{4}O_{6}. _Syn._ MANGANESII TARTRAS, L.

_Prep._ By saturating a solution of tartaric acid with most manganous carbonate. Alterative and tonic.--_Dose_, 4 to 12 gr.

=Manganate of Barium.= BaMnO_{4}. Green insoluble powder, obtained by fusing barium hydrate, pota.s.sium chlorate, and manganic peroxide together, and washing the product.

=Manganate of Pota.s.sium.= K_{2}MnO_{4}. Finely powdered manganic peroxide, pota.s.sium chlorate, and pota.s.sium hydrate, made into a thick paste with water, and heated to dull redness. The fused product is treated with a small quant.i.ty of water, and crystallised by evaporation in vacuo.

Dark green, almost black crystals, readily soluble in water, but decomposed by excess, or by acids into manganic peroxide, and pota.s.sium permanganate.

=Manganate of Sodium.= Na_{2}MnO_{4}. Prepared on the large scale by heating a mixture of manganic peroxide and sodium hydrate to redness in a current of air. Used in strong solution as a disinfectant under the name of "Condy's green fluid."

=Manganic Acid.= H_{2}MnO_{4}. This acid has not yet been obtained free, but some of its salts are extensively employed as disinfectants, as "green Condy's fluid." The chief compounds are the following:--

=Manganic Hydrate.= Mn_{2}(HO)_{6}. _Syn._ HYDRATED SESQUIOXIDE OF MANGANESE. Found native as "manganite," in reddish-brown crystals. _Prep._ By pa.s.sing a current of air through recently precipitated and moist manganous hydrate. Soft dark brown powder converted into the oxide by heat.

=Manganic Oxide.= Mn_{2}O_{3}. _Syn._ SESQUIOXIDE OF MANGANESE. Found native as "Braumite," and readily formed by exposing manganous hydrate to the action of air, and drying, or by gently igniting the peroxide brown or black powder decomposed by heat.

=Manganic Peroxide.= MnO_{2}. _Syn._ PERMANGANIC OXIDE, BINOXIDE OF MANGANESE, PEROXIDE OF MANGANESE, BLACK OXIDE OF MANGANESE, OXIDE OF MANGANESE, MANGANESII OXIDUM NIGRUM (B. P.), MANGANESII BINOXYDUM (Ph.

L.), MANGANESE OXYDUM (Ph. E.).

It is the only oxide of manganese that is directly employed in the arts.

It is a very plentiful mineral production, and is found in great abundance in some parts of the West of England. The manganese of the shop is prepared by washing, to remove the earthy matter, and grinding in mills.

The blackest samples are esteemed the best. It is chiefly used to supply oxygen gas, and in the manufacture of gla.s.s and chlorine; in dyeing and to form the salts of manganese. It has been occasionally employed in medicine, chiefly externally in itch and porrigo, made into an ointment with lard. It has been highly recommended by Dr Erigeler in scrofula.

Others have employed it as an alterative and tonic with variable success.

When slowly introduced into the system during a lengthened period, it is said to produce paralysis of the motor nerves. (Dr Coupar.)--_Dose_, 3 to 12 gr., or more, thrice daily, made into pills.

_Pur._ Native binoxide of manganese (pyrolusite) is usually contaminated with variable proportions of argillaceous matter, calcium carbonate, ferric oxide, silica, and barium sulphate, all of which lower its value as a source of oxygen, and for the preparation of chlorine. The richness of this ore can, therefore, be only determined by an a.s.say for its princ.i.p.al ingredient.

_a.s.say._ There are several methods adopted for this purpose, among which the following recommend themselves as being the most accurate and convenient.

1. A portion of the mineral being reduced to very fine powder, 50 gr. of it are put into the little apparatus employed for the a.n.a.lysis of carbonates described at page 406, together with about 1/2 fl. oz. of cold water, and 100 gr. of strong hydrochloric acid, the latter contained in the little tube (_b_); 50 gr. of crystallised oxalic acid are then added, the cork carrying the chloride of calcium tube fitted in, and the whole quickly and accurately weighed or counterpoised; the apparatus is next inclined so that the acid contained in the small tube may be mixed with the other contents of the flask, and the reaction of the ingredients is promoted by the application of a gentle heat; the disengaged chlorine resulting from the mutual decomposition of the hydrochloric acid and the manganic peroxide converts the oxalic acid into carbonic acid gas, which is dried in its pa.s.sage through the chloride of calcium tube before it escapes into the air. As soon as the reaction is complete, and the residual gas has been driven off by a momentary ebullition, the apparatus is allowed to cool, when it is again carefully and accurately weighed. The loss of weight in grains, if doubled, at once indicates the percentage richness of the mineral examined in manganic peroxide; or, more correctly, every grain of carbonic anhydride evolved represents 1982 gr. of the peroxide.

2. (Fresenius and Will.) The apparatus employed is the 'alkalimeter'

figured at page 30. The operation is similar to that adopted for the a.s.say of alkalies, and is a modification of the oxalic acid and sulphuric acid test for manganese, originally devised by M. Berthier. The standard weight of manganic peroxide recommended to be taken by Fresenius and Will is 291 grammes, along with 65 to 7 grammes of neutral pota.s.sium oxalate. The process, with quant.i.ties altered to adapt it for employment in the laboratories of these countries, is as follows:--Manganic peroxide (in very fine powder), 50 gr.; neutral pota.s.sium oxalate (in powder), 120 gr.; these are put into the flask _A_ (see _engr._, p. 31), along with sufficient water to about 1-4th fill it; the flask _A_ and _B_ (the latter containing the sulphuric acid) are then corked air-tight, and thus connected in one apparatus, the whole is accurately weighed. The opening of the tube _b_ being closed by a small lump of wax, a little sulphuric acid is sucked over from the flask _B_ into the flask _A_; the disengagement of oxygen from the manganese immediately commences and this reacting upon the oxalic acid present, converts it into carbonic anhydride gas, which pa.s.sing through the concentrated sulphuric acid in the flask _B_, which robs it of moisture, finally escapes from the apparatus through the tube _d_. As soon as the disengagement of carbonic acid ceases, the operator sucks over a fresh portion of sulphuric acid, and this is repeated at short intervals, until bubbles of gas are no longer disengaged. The little wax stopper is now removed, and suction is applied at _h_ until all the carbonic acid in the apparatus is replaced by common air. When the whole has become cold it is again weighed. The loss of weight, doubled, indicates the amount of pure manganic peroxide, in the sample, as before.

3. (Otto.) 50 gr. of the sample reduced to very fine powder are mixed in a gla.s.s flask, with hydrochloric acid 1-1/2 fl. oz., diluted with 1/2 oz. of cold water, and portions of ferrous sulphate, from a weighed sample, immediately added, at first in excess, but afterwards in smaller doses, until the liquid ceases to give a blue precipitate with red prussiate of potash, or to evolve the odour of chlorine; heat being employed towards the end of the process. The quant.i.ty of ferrous sulphate consumed is now ascertained by again weighing the sample. If the peroxide examined was pure, the loss of weight will be 317 gr.; but if otherwise, the percentage of the pure peroxide may be obtained by the rule of three. Thus: suppose only 298 gr. of the sulphate were consumed, then

317 : 100 :: 298 : 94,

and the richness of the sample would be 94%. The percentage value of the oxide for evolving chlorine may be obtained by multiplying the weight of the consumed ferrous sulphate by 2588, which, in the above case, would give 76% of chlorine. For this purpose, as well as for chlorometry, the ferrous sulphate is best prepared by precipitating it from its aqueous solution with alcohol, and drying it out of contact with air until it loses its alcoholic odour.

_Obs._ Before applying the above processes it is absolutely necessary that we ascertain whether the peroxide examined contains any carbonates, as the presence of these would vitiate the results. This is readily determined by treating it with a little dilute nitric acid:--if effervescence ensues, one or more carbonates are present, and the sample, after being weighed, must be digested for some time in dilute nitric acid in excess, and then carefully collected on a filter, washed, and dried. It may then be a.s.sayed as before. The loss of weight indicates the quant.i.ty of carbonates present, with sufficient accuracy for technical purposes. The determination of this point is the more important, as these contaminations not merely lessen the richness of the mineral in pure manganic peroxide, but also cause a considerable waste of acid when it is employed in the manufacture of chlorine.

=Permanganic Acid.= HMnO_{4}. Obtained by distilling cautiously pota.s.sium permanganate and sulphuric acid. Dark violet-black liquid, green by reflected light, and rapidly absorbing water forming a violet solution.

Oxidises organic matter with explosive violence.

=Permanganate of Barium.= Ba(MnO)_{45}. Black soluble prisms, formed by decomposing silver permanganate by means of barium chloride, and cautiously evaporating.

=Permanganate of Pota.s.sium.= KMnO_{4}. _Prep._ Pota.s.sium chlorate, or nitrate, and pota.s.sium hydrate are made into a paste with water, and manganic peroxide added; the ma.s.s is dried and heated to redness. The residue is boiled with water, filtered through asbestos, and evaporated down and recrystallised.

Dark purple, red, almost black anhydrous long prisms, readily soluble in 16 pints of water. Decomposed in presence of acids by most organic matter.

=Permanganate of Silver.= AgMnO_{4}. _Prep._ Precipitate a strong solution of silver nitrate by means of a concentrated solution of pota.s.sium permanganate. Small black prisms, soluble in 100 parts of water, with a purple colour.

=Permanganate of Sodium.= NaMnO_{4}. Obtained as a dark purple liquid by pa.s.sing a current of carbonic anhydride through sodium manganate. Condy's red fluid is chiefly a sodium permanganate dissolved in water.

=MANGE.= An eruptive disease, corresponding to the itch in man, resulting from the burrowing into the skin of minute animalcules (mites or _acari_), and common to several domestic animals, more especially the dog and horse.

Like the itch, it is contagious. The causes are confinement, dirt, and bad living. The treatment should consist in the immediate removal of the cause, the frequent use of soft soap and water, followed by frictions with sulphur ointment, solution of chloride of lime or sporokton, the administration of purgatives, and a change to a restorative diet. Dun states that in India a very efficient remedy for mange is employed by the native farriers, which consists of castor oil seeds well bruised, steeped for twelve hours in sour milk, and rubbed into the skin, previously thoroughly cleansed with soap and water. "The itchiness disappears almost immediately and the acari are speedily destroyed." A dressing consisting of 1 oz. of chloride of zinc (Burnett's disinfectant fluid) and 1 quart of water may also be applied with advantage.

=MAN"GEL WUR'ZEL.= _Syn._ MANGOLD-WURZEL, HYBRID BEET, ROOT OF SCARCITY.

The _Beta vulgaris_, var. _campestris_, a variety of the common beet. The root abounds in sugar, and has been used in Germany as a subst.i.tute for bread in times of scarcity. In these countries it is chiefly cultivated as food for cattle. The young leaves are eaten as spinach. The percentage composition of mangold wurzel is as follows:--Flesh-formers (alb.u.menoid bodies), 154; heat and fat-formers (sugar, &c.) 860; indigestible fibre, 112; ash, 096; 8778.

=MAN'HEIM GOLD.= A gold-coloured bra.s.s. See GOLD (Dutch).

=MAN'NA= _Syn._ MANNA (B. P., Ph. L., E., & D.), L. A concrete exudation from the stem of _Fraxinus ornus_ and _F. rotundifolia_, obtained by incision. (B. P.) "The juice flowing from the incised bark" of "_Fraxinus rotundifolia_ and _F. ornus_, hardened by the air." (Ph. L.) The finest variety of this drug is known as flake manna, and occurs in pieces varying from 1 to 6 inches long, 1 or 2 inches wide, and 1/2 to 1 inch thick. It has a yellowish-white or cream colour; an odour somewhat resembling honey, but less pleasant, a sweet, mawkish taste; and is light, porous, and friable. It is laxative in doses of 1 to 2 oz.

=Manna Fact.i.tious=, made of a mixture of sugar, starch, and honey, with a very small quant.i.ty of scammony to give it odour and flavour, and to render it purgative, has been lately very extensively offered in trade, and met with a ready sale.

=MAN'NACROUP.= A granular preparation of wheat deprived of bran, used as an article of food for children and invalids. (Brande.)

=MAN'NITE.= C_{6}H_{14}O_{6}. _Syn._ MANNA SUGAR, MUSHROOM S.; MANNITA, L.

A sweet, crystallisable substance, found in manna and in several other vegetable productions. It has been formed artificially by the action of sodium-amalgam upon an alkaline solution of cane sugar.

_Prep._ 1. Digest manna in boiling rectified spirit, and filter or decant the solution whilst hot; the mannite crystallises as the liquid cools in tufts of slender, colourless needles.

2. (Ruspini.) Manna, 6 lbs.; cold water (in which the white of an egg has been beaten), 3 lbs.; mix, boil for a few minutes, and strain the syrup through linen whilst hot; the strained liquid will form a semi-crystalline ma.s.s on cooling; submit this to strong pressure in a cloth, mix the cake with its own weight of cold water, and again press it; dissolve the cake thus obtained in boiling water, add a little animal charcoal, and filter the mixture into a porcelain dish set over the fire; lastly, evaporate the filtrate to a pellicle, and set the syrup aside to crystallise. Large quadrangular prisms; perfectly white and transparent.

_Prop., &c._ Mannite has a powerfully sweet and agreeable taste; dissolves in 5 parts of cold water and about half that quant.i.ty of boiling water; freely soluble in hot, and slightly so in cold alcohol; fuses by heat without loss of weight; with sulphuric acid it combines to form a new acid compound. It is distinguished from the true sugars by its aqueous solution not being susceptible of the vinous fermentation, and not possessing the property of rotary polarisation. When pure, it is perfectly dest.i.tute of purgative properties. It is now extensively imported from Italy, and is chiefly used to cover the taste of nauseous medicines, and as a sweetmeat.

=MANURES'.= Substances added to soils to increase their fertility. The food of vegetables, as far as their organic structure is concerned, consists entirely of inorganic compounds; and no organised body can serve for the nutrition of vegetables until it has been, by the process of decay, resolved into certain inorganic substances. These are carbonic acid, water, and ammonia, which are well known to be the final products of putrefaction. But even when these are applied to vegetables, their growth will not proceed unless certain mineral substances are likewise furnished in small quant.i.ties, either by the soil or the water used to moisten it.

Almost every plant, when burned, leaves ashes, which commonly contain silica, pota.s.sa, and phosphate of lime; often, also, magnesia, soda, sulphates, and oxide of iron. These mineral bodies appear to be essential to the existence of the vegetable tissues; so that plants will not grow in soils dest.i.tute of them, however abundantly supplied with carbonic acid, ammonia, and water. The carbon of plants is wholly derived from carbonic acid, which is either absorbed from the atmosphere, and from rain water, by the leaves, or from the moisture and air in the soil, by the roots. Its carbon is retained and a.s.similated with the body of the plant, while its oxygen is given out in the gaseous form; this decomposition being always effected under the influence of light at ordinary temperatures. The hydrogen and oxygen of vegetables, which, when combined with carbon, const.i.tute the ligneous, starchy, gummy, saccharine, oily, and resinous matters of plants, are derived from water chiefly absorbed by the roots from the soil. The nitrogen of vegetables is derived chiefly, if not exclusively, from ammonia, which is supplied to them in rain, and in manures, and which remain in the soil till absorbed by the roots.

According to the celebrated 'mineral theory' of agriculture advanced by Liebig a soil is fertile or barren for any given plant according as it contains those mineral substances that enter into its composition. Thus, "the ashes of wheat-straw contain much silica and pota.s.sa, whilst the ashes of the seeds contain phosphate of magnesia. Hence, if a soil is deficient in any one of these, it will not yield wheat. On the other hand, a good crop of wheat will exhaust the soil of these substances, and it will not yield a second crop till they have been restored, either by manure or by the gradual action of the weather in disintegrating the subsoil. Hence the benefit derived from fallows and from the rotation of crops.

"When, by an extraordinary supply of any one mineral ingredient, or of ammonia, a large crop has been obtained, it is not to be expected that a repet.i.tion of the same individual manure next year will produce the same effect. It must be remembered that the unusual crop has exhausted the soil probably of all the other mineral ingredients, and that they also must be restored before a second crop can be obtained.

"The salt most essential to the growth of the potato is the double phosphate of ammonia and magnesia; that chiefly required for hay is phosphate of lime; while for almost all plants pota.s.sa and ammonia are highly beneficial."

From these principles we "may deduce a few valuable conclusions in regard to the chemistry of agriculture. First, by examining the ashes of a thriving plant, we discover the mineral ingredients which must exist in a soil to render it fertile for that plant. Secondly, by examining a soil, we can say at once whether it is fertile in regard to any plants the ashes of which have been examined. Thirdly, when we know the defects of a soil, the deficient matters may be easily obtained and added to it, unmixed with such as are not required. Fourthly, the straw, leaves, &c., of any plant, are the best manure for that plant, since every vegetable extracts from the soil such matters alone as are essential to it. This important principle has been amply verified by the success attending the use of wheat-straw, or its ashes, as manure for wheat, and of the chippings of the vines as a manure for the vineyard. When these are used (in the proper quant.i.ty) no other manure is required. Fifthly, in the rotation of crops, those should be made to follow which require different materials; or a crop which extracts little or no mineral matter, such as peas, should come after one which exhausts the soil of its phosphates and pota.s.sa."

(Liebig.)

The experiments of Messrs Lawes and Gilbert have forced upon them opinions differing from those of Baron Liebig on some important points in relation to his 'mineral theory,' which endeavours to prove that "the crops on a field diminish or increase in exact proportion to the diminution or increase of the mineral substances conveyed to it in manure." The results obtained by the English investigators appear to prove that it is impossible to get good crops by using mineral manures alone, and that nitrogenous manures (farm-yard manure, guano, ammoniacal salts, &c.) are fertilising agents of the highest order.

Of the chemical manures now so much used bone-dust is, perhaps, the most important, as it supplies the phosphates which have been extracted by successive crops of gra.s.s and corn, the whole of the bones of the cattle fed on these crops having been derived from the soil; its gelatin also yields ammonia by putrefaction. Guano acts as a source of ammonia, containing much oxalate and urate of ammonia, with some phosphates.

Nightsoil and urine, especially the latter, are most valuable for the ammonia they yield, as well as for the phosphates and pota.s.sa; but are very much neglected in this country, although their importance is fully appreciated in Belgium, France, and China. Nitrate of soda is valued as a source of nitrogen.