# Scientific Memoirs/1/Experiments on the Essential Oil of the Spirea Ulmaria, or Meadow-Sweet

From J. C. Poggendorff's Annalen der Physik und Chemie; Berlin, Second Series, vol. v. p. 596.
Article VIII.
Experiments on the Essential Oil of the Spiræa Ulmaria, or Meadow-Sweet; by Dr. Löwig, Professor of Chemistry at Zurich.
From J. C. Poggendorff's Annalen der Physik und Chemie; Berlin, Second Series, vol. v. p. 596.
WHILST by the examination of plants and vegetable matters we have acquired the knowledge of a great number of oxyacids with compound radicals, with the exception of prussic acid no such hydracid has been shown to exist in organic nature; and of hydracids with ternary radicals, if we except the sulphocyanic acid, we have not the slightest knowledge.
The constancy of the phænomena which oil of bitter almonds presents, have not only led to the positive knowledge of the existence of ternary radicals, but also to the fact that oxyacids exist with ternary bases containing oxygen.
By means of the experiments made with the essential oil of the blossoms of the Spiræa Ulmaria, described in the following treatise, the first hydracid with a ternary radical in organic nature has been discovered in a most extraordinary manner, and they give every reason to hope that the radical of the same may also be isolated.
The reader must excuse the circumstances that the experiments are not carried further, and that some of the most important appearances when remarked have not been further pursued, as for all the experiments, there was only a very small quantity of material at the disposal of the experimenter.
If also, on account of the small quantity of the oil which could be subjected to research, each experiment was conducted only on a small scale, especially as regards the analysis, and could only be seldom repeated, the coincidence of each separate experiment may perhaps in part supply the want of repetition. Should however the analytical results experience any small change by later repeated experiments, we may nevertheless be sure that the facts themselves of which this Memoir treats will lose nothing in importance.
By means of this communication the attention of chemists may be drawn to the oil of the Spiræa, so that not only a repetition of these experiments, but also a further extension of them may be expected with certainty from other chemists.
​M. Pagenstuher, an apothecary in Berne, had already drawn attention to the oil and distilled water of the blossoms of Spiræa Ulmaria in a treatise which may be found in Buchner's Repertorium, vol. {{sc|xlix.} p.337. He there describes exactly almost all the combinations which are the subject of this Memoir; and had he made analyses of the elements with only a few substances, the real nature, not only of the oil itself, but also several decompositions and recompositions which it experiences would not then have escaped him.
M. Pagenstuher had the kindness to give me the oil for all the investigations, and also to communicate to me his observations made up to that time. All his experiments which were of any importance on the present subject are incorporated into this Memoir, so that in many respects the present work may be considered as undertaken conjointly with M. Pagenstuher. To facilitate the general view of the following experiments, a few of the leading results may be first stated.
The oil of the blossoms of the Spiræa Ulmaria is a hydracid; it consists of one eq. of a radical = C 12 H 5 O 4, and one eq. of hydrogen, which uniting with the radical forms an acid. If the hydrogen, which by uniting with the radical forms the acid, be oxidized by nitric acid, 4 additional eqs. of oxygen are taken up by the radical, thus forming the oxyacid of the same radical. Instead of 1 eq. of hydrogen, the radical can unite with 1 eq. of chlorine, bromine, iodine, or even of a metal. These latter combinations are also formed when the hydracid is made to act on metallic oxides. With ammonia, on the contrary, the hydracid unites without undergoing any change. From these combinations the following compounds result:
* C 12 H 5 O4 + H
* C 12 H 5 O4 + CI
* C 12 H 5 O 4 + Br
* C 12 H 5 O4 + I
* C 12 H 5 O4 + P
* C 12 H 5 O4 + O4
* (C 12 H 5 4+ H) + N H 3 or ammonia.
The radical is designated by the name Spiræoyl, or for the conve-nience of shortness Spiroil. Another name would have been chosen for it had not a similar nomenclature been already applied to another substance nearly allied to it. It is always doubtful policy to derive the name of a vegetable principle from the plant in which it is first discovered, for generally with great probability the same body may be found in other plants. Names which designate any principal peculiarity of the substance are therefore in such cases always preferable. One of the peculiarities of spiroil is its property of forming yellow compounds with oxygen, and with the metals, alkalies, and earths; a name therefore which had reference to this quality would have been very suitable. A name ​however, is only a sign for a certain expression, and thus considered it is perfectly indifferent what name may be chosen for any substance.
Hydrospiroilic Acid.
The fluid oil of the blossoms of the Spiræa Ulmaria is hydrospiroilic acid. This may be obtained by distilling the flowers with water; about as much water is to be distilled off as was originally employed.
The product of the distillation is however subjected to a redistillation till about ⅕th is come over in the receiver. A concentrated aqueous solution of the oil is thus obtained, and the oil itself, though only in very minute quantities. The oil is heavier than water, is of a light yellow colour, and possesses the odour of the blossoms in a very great degree. It mixes in all proportions with alcohol and æther, and is slightly soluble in water. It causes a burning sensation on the tongue. The fumes which come over during the distillation of the oil first render litmus-paper green, and then bleach it. The aqueous solution of the oil first of all slightly reddens tincture of litmus, and then deprives it of its colour excepting a greenish shade. It is inflammable, and burns with a shining smoky flame. If the oil be passed through a red-hot tube containing pieces of iron, neither ammonia nor prussic acid is obtained nor can the formation of any sulphuret of iron be detected. The oil does not experience any change either in dry or moist oxygen gas; it volatilizes unchanged. It solidifies at a temperature of – 20° *. Its boiling-point is about + 85°*, when it evaporates entirely without leaving any residue.
With the bases of salts, namely, with the alkalies and alkaline earths, it easily combines, forming insoluble or difficultly soluble compounds.
Concentrated sulphuric acid converts the oil into a black carbonaceous mass. Chlorine and bromine decompose it instantaneously, hydrochloric or hydrobromic acid and chloride or bromide of spiroil being formed. Nitric acid, if not too concentrated, immediately forms spiroilic acid; if however the acid be very concentrated and fuming, it immediately changes it into a yellow, very volatile, bitter-tasting compound, having the appearance of butter.
The experiments on the composition of the anhydrous oil, as well as the other compounds, were made in the usual manner with oxide of copper.
| 0.290 grms. of the oil gave | 0-694 | carb. acid | 191.89 | carbon |
| 0.290 | 0.145 | water | 16-10 | hydrogen; |
according to which 290 parts of the oil contain
| Carbon | 191.89 | 66 . 17 |
| Hydrogen | 16.10 | 5.55 |
| Oxygen | 82.01 | 28.28 |
| | 290.00 | 100.00 |
Probably Centigrade.—Translator. ​from whence we may deduce the following eq.
| | | | | | | in 100 parts |
| 12 | eqs. | Carbon | = | 73-56 | = | 66*92 |
| 6 | — | Hydrogen | = | 6*00 | = | 8-35 |
| 4 | — | Oxygen | = | 32-00 | = | 27-73 |
| 1 | Hydrospiroilic acid | 111 .56 | | 100-00 |
The combination of the oil with copper was also subjected to analysis. This compound was obtained by agitating together an aqueous solution of the oil with freshly prepared quite pure hydrated oxide of copper, taking care that the oil should be in excess; and the green compound thus obtained was dried at + 160°. At this temperature the combination is not decomposed, which is evident, as the oil may again be obtained unaltered on the addition of an acid. By other means, by double decomposition for instance, the combination with copper may be obtained, but not quite pure, as it then contains slight traces of the acid which was united with the copper, even if excess of alkali be employed as a precipitant.
| 0.1 74 | grm of the compound with copper yielded | 0-324 | c. a. | 89-58 | carbon |
| 0-174 | | 0-054 | water | 5-99 | hydr. |
Also by burning the cupreous combination in contact with the air, 0-130 of the compound yielded
0-03719 oxide of copper 29.68 copper.
If now in the cupreous combination the copper is considered to have been in the metallic state we obtain
| Carbon | = | 89*58 | or | 51-48 |
| Hydrogen | = | 5-99 | — | 3-44 |
| Oxygen | = | 38-71 | — | 22-20 |
| Copper | = | 39-72 | — | 22-88 |
| | | 174-00 | | 100-00 |
which in eq.
| 12 | eqs. | Carbon | 73-56 | or | 51-71 |
| 5 | — | Hydrogen | 5-00 | — | 3-51 |
| 4 | — | Oxygen | 32-00 | — | 22-51 |
| 1 | — | Copper | 31-70 | — | 22-27 |
| 1 | eq. | Spiroilide of copper | 142-26 | | 100-00 |
These experiments confirm the truth of the above-mentioned view, that the oil is a hydracid with a ternary base, and they likewise show that the action of this hydracid with metals is exactly the same as that of those which were before known.
This view receives still further confirmation by the fact that when ​chlorine is passed over one of the metallic combinations, as spiroilide of copper or spiroilide of silver, chloride of copper or silver, and chloride of spiroil are formed without the slightest trace of muriatic acid.
The most striking proof, however, that the oil is really a hydracid is, that when potassium is brottght into contact vjith the oil over mercury and gently warmed, hydrogen is evolved, spiroilide of potassium being formed, from which latter the oil may again be obtained, possessed of all its original properties, by the action of muriatic acid.
The action of the oil and potassium, which at common temperatures goes on but slowly, is by a very gentle heat so much increased, that during the evolution of the hydrogen the combination of the spiroil and potassium is attended with the evolution of heat and light. At the same time not the slightest trace of carbon or of any carbonaceous matter is deposited, and the hydrogen which is evolved is quite pure. If the oil which is employed for these experiments be not quite free from water, evolution of hydrogen takes place as soon as it comes into contact with the potassium; this however ceases (almost entirely) in a few moments: if however the apparatus be now gently warmed, which may be done by gradually bringing near a glowing coal, the evolution of gas begins again in great quantity and with the same violence as when the anhydrous oil was employed.
Hydrospiroilate of Ammonia.
If a concentrated solution of ammonia is poured upon pure hydrospiroilic acid, the fluid mixture after a few seconds is converted into a solid mass of hydrospiroilate of ammonia, giving out heat and undergoing a considerable increase of bulk during the action: it may be freed from water and excess of acid by washing with alcohol. It possesses a weak aromatic smell resembling a rose, is tasteless, and has a yellow colour. The compound is almost insoluble in water, which nevertheless when left for some time in contact with it, acquires a yellow colour. In common cold spirit of wine the hydrospiroilate of ammonia is only slightly soluble, but on the contrary it is dissolved in great quantities both in hot and cold pure alcohol. If the boiling solution be allowed to cool, hydrospiroilate of ammonia is obtained in transparent delicate tufts of acicular crystals of a light yellow colour. If it be preserved in close vessels in a moist state it is decomposed ; after a short time it becomes gradually black, then semifluid, ammonia is evolved, and an exceedingly strong penetrating odour of oil of roses is perceptible.
At the boiling-point of water, hydrospiroilate of ammonia undergoes no change.
At + 115° it is fluid, melting like wax; heated a few degrees above its boiling-point it volatilizes in the form of a yellow vapour without leaving-any residue and without undergoing any alteration. If solution ​of potash or soda be poured over this salt, the ammoniacal odour is not immediately developed, but becomes so after continued contact or the application of heat. This circumstance might lead to the supposition, that in this compound there is a similar relation between the acid and the alkali as in the cyanate of ammonia.
At the same time it must be observed, that acids immediately decompose this compound, the oil being deposited, undecomposed, and a corresponding salt of ammonia formed. 0*21 3grm. of hydrospiroilate of ammonia obtained in crystals by evaporating the alcoholic solution was decomposed by dilute muriatic acid ; the solution thus obtained was evaporated to dryness in a water-bath, and the remaining neutral saline mass again dissolved in water. By precipitation with nitrate of silver, 0"239grm. of chloride of silver were obtained; as these correspond to 0'0288 of ammonia, the above 0*21 3grm. consist of
| Ammonia | 0-0288, | or in 100 parts | 13-52 |
| Hydrospiroilic acid | 0-1850 | | 86-48 |
| | 0-2138 | | 100-00 |
| 1 equivalent ammonia | = | 17-18 | or | 13-38 |
| 1 hydrospiroilic acid | = | 111 'BS | — | 86*62 |
| 1 eq. hydrospiroilate of ammonia | 128-74 | | 100-00 |
Spiroilide of Potassium.
The spiroilide of potassium may be obtained either by gently heating together potassium and hydrospiroilic acid, hydrogen being evolved, or by bringing together either the pure or the watery hydrospiroilic acid and solution of potash. Spiroilide of potassium is difficulty soluble in water.
If the aqueous solution be slowly evaporated, small prismatic straw-coloured crystals are obtained. Left in contact with the air it soon decomposes, absorbing moisture and carbonic acid, like the hydrospiroilate of ammonia. It may nevertheless be kept unaltered for a long time in close vessels. The smell resembling that of roses is likewise perceptible during the decomposition of this substance; at the end, carbonate of potash remains.
| 1 eq. potassium | 39*20 | 26*87 | 24-93 |
| 1 eq. spiroil | 110-56 | 73-13 | 75-07 |
| 1 eq. spiroilide potassium | 149-76 | 100-00 | 100.00 |
Spiroilides of Sodium, Calcium and Barium. These possess similar properties to the spiroilide of potassium, but the two latter compounds are still less soluble in water.
Spiroilide of Magnesium may be obtained by agitating together the ​watery hydrospiroilic acid and hydrate of magnesia. It appears as a light yellow and almost insoluble powder.
Protospiroilide of Iron. The aqueous solution of hydrospiroilic acid has no action on protochloride of iron; on the addition of ammonia however a deep violet blue precipitate falls.
Sesquispiroilide of Iron. Sesquichloride of iron immediately changes the colour of the aqueous solution of hydrospiroilic acid to a fine deep cherry-red colour, without any precipitate.
If this fluid be exposed to the air it loses its red colour in a short time, and a pure solution of sesquichloride of iron remains, in which a fresh addition of hydrospiroilic acid again causes the cherry-red colour to appear.
Subspiroilide of Copper. Hydrospiroilic acid has no action on the subchloride of copper; a slight addition of ammonia however causes a light brown precipitate in this mixture.
Protospiroilide of Copper. This compound is best obtained by agitating together an aqueous solution of hydrospiroilic acid and newly prepared hydrated oxide of copper. This latter immediately loses its blue colour and becomes green.
If solutions of sulphate of copper and spiroilide of potassium be mixed, a voluminous precipitate falls, which however is but slowly deposited and possesses a distinct ciystalline texture.
Spiroilide of Zinc. When oxide of zinc is agitated with the aqueous solution of hydrospiroilic acid, it very soon absorbs the acid from the water, which latter acquires a yellow colour. By evaporation under the airpump, a yellow pulverulent substance is obtained. The aqueous solution of spiroilide of zinc is coloured cherry-red by sesquichloride of iron.
Spiroilide of Lead. When pure oxide of lead is brought into contact with hydrospiroilic acid no spiroilide of lead is formed. Newly prepared hydrated oxide of lead however, when left for some time in contact with the aqueous acid, becomes converted into a light yellow pow- der, consisting of small shining laminae of spiroilide of lead.
Spiroilide of Mercury. The aqueous solution of the acid has no action on red oxide of mercury when they are left together in close vessels, even though frequently agitated.
Spiroilide of mercury is however obtained when a concentrated solution of corrosive sublimate is poured over hydrospiroilate of ammonia. A pale straw-coloured flocky voluminous precipitate is formed. Spiroilide of Silver. Oxide of silver is partially dissolved by the aqueous solution of hydrospiroilic acid.
The solution is of a yellow colour, and has a bitter metallic taste. By evaporation in vacuo a brownish black residue is obtained, which inflames with detonation in the candle, leaving behind metallic silver. ​The undissolved portion of the oxide, which has also acquired a brownish black colour, possesses the same property.
The greater number of the compounds of the metals with spiroil may be obtained by double affinity, but for this purpose the spiroilic combinations must be difficultly soluble or insoluble, and very concentrated solutions of easily soluble salts must be employed. For this reason, in order to obtain the combination with lime, solution of chloride of calcium is employed; for the combination with zinc, acetate of zinc; for the magnesian compound, chloride of magnesium; and for the compounds with iron, the proto- and the sesqui-chloride of iron. The best combination of spiroil to employ is the hydrospiroilate of ammonia, over which the concentrated solution of the salt is to be poured. The spiroilide of barium, which is be&t obtained by saturating baryta water with the acid, may be advantageously employed in the state of a solution for the preparation of several of the compounds of spiroil. The compounds as obtained by double decomposition are seldom crystalline, but are obtained almost always as a fine and soft powder.
Spiroilic Acid.
If hydrospiroilic acid be gently and carefully heated with nitric acid not too concentrated, and care be taken that the acid be not used in excess, the oil is converted under evolution of nitrous fumes into a solid crystalline body; the substance thus obtained is spiroilic acid.
If the gas which is evolved during this operation be conducted into a solution of chloride of barium mixed with ammonia, not the slightest trace of carbonate of barytes will be formed.
The acid is nearly devoid of odour: its taste is at first not striking ; afterwards however much irritation in the throat, and a strong inclination to cough are experienced. Spiroilic acid is fusible, and shows strong inclination to crystallize, especially on returning to the solid state after having been heated. In close vessels it may be sublimed; nevertheless by this operation the greater part is decomposed, leaving behind a carbonaceous mass.
In the anhydrous state, as it is obtained by fusion, spiroilic acid is of a pale yellow colour.; if however it be exposed to the air it deliquesces and becomes of a deep yellow colour. It is easily soluble in alcohol and æther; only slightly so however in water. The solutions stain the skin and nails permanently yellow. Litmus-paper is stained deep yellow; no reddening effect can however be observed. If the alcoholic solution of the spiroilic acid be left to spontaneous evaporation, the acid is obtained in delicate transparent prisms of a golden yellow colour.
| 1st, | 0*190 fused spiroilic acid gave 0*350 carbon = 96*77 car. |
| | 0*190 ditto gave 0*060 water =6*66 hydr. |
| 2ndly, | 0*243 ditto gave 0*450 carb = 1 24*42 carb. 0*0759= 8*33 hyd. |
| Carbon | 50.92 | …… | 51-18 |
| Hydrogen | 3-50 | …… | 3*43 |
| Oxygen | 45-58 | …… | 45-39 |
| | 100.00 | 100.00 |
or reckoned in equivalents,—
| 12 | eqs. | carbon | 73-56 | …… | 51-58 |
| 5 | — | hydrogen | 5-00 | …… | 3-50 |
| 8 | — | oxygen | 64-00 | …… | 44-92 |
| 1 eq. spiroilic acid | 142*56 | | 100.00 |
From these experiments we may deduce, that in the moment that the one equivalent of hydrogen of the hydrospiroilic acid is oxidized, four more equivalents of oxygen are taken up by the radical. This likewise explains the formation of so large a portion of nitrous acid, even when a very small quantity only of the oil is employed.
It appeared probable that during the oxidation a portion of nitric or nitrous acid was absorbed by the radical, and this opinion was supported by the fact, that spiroilic acid stains the skin and nails permanently yellow,— a property which is likewise possessed by the spiroilide of potassium and several other metallic spiroilides; several experiments were undertaken to detect the nitrogen or the acid, but unsuccessfully with regard to either.
If spiroilic acid be slightly heated with potassium over mercury, a most violent evolution of heat and light suddenly takes place, by which the vessel is always broken with great violence. Even should excess of potassium be employed in this experiment, only a portion of the spiroilic acid is decomposed; a porous carbon is deposited, and a mixture of spiroilide of potassium and carbonate of potash is formed.
The pure alkalies unite very readily with spiroilic acid, forming yellow compounds, by evaporating the aqueous solutions of which small yellow crystals may be obtained.
If spiroilic acid be dissolved in æther, and the solution agitated with solutions of potash or soda, the æther is immediately abstracted from the acid. The alkaline salts of spiroilic acid are also soluble in alcohol.
If ammonia be saturated with spiroilic acid, a deep blood-red solution is obtained. If this be evaporated to dryness a yellow residue remains, which if rubbed with caustic alkali immediately develops a strong ammoniacal odour. If spiroilate of ammonia be subjected to a high temperature in close vessels it is decomposed, some ammonia is evolved, and an oily body comes over, the exact nature of which has not been determined on account of the minuteness of the quantity.
​The aqueous solution of spiroilate of soda gives with acetate of lead a yellow, and with salts of copper a green, precipitate.
Sesquichromate of iron is not precipitated by spiroilate of soda, but is coloured deep cherry-red by it, as well as by the spiroilide.
If the salts of spiroilic acid are heated in contact with the air, they detonate briskly, leaving behind either a pure or carbonated base, and a soft powdery carbon.
If spiroilic acid be mixed with an easily inflammable substance, as sulphur, the mixture detonates when heated.
Fuming nitric acid acts very violently upon spiroilic acid; fumes of nitrous acid are immediately evolved, whilst a yellow semifluid mass is formed, which solidifies only after several days. This yellow substance has an intensely bitter taste, and colours the saliva, skin, and nails, &c. deep yellow; it is fusible and may be distilled, and possesses in a striking degree the smell of fresh butter; no oxalic acid is formed. Submitted to distillation with water, it distils over undecomposed with the water, partially dissolved and partly as a yellow powder.
If the residue of the aqueous solution after the yellow body has gone over be slowly evaporated, transparent colourless prismatic crystals are obtained, the nature of which requires further investigation.
An analysis of this substance, which appeared to possess acid properties, was several times commenced; but even by the most careful application of heat, the oxide of copper was always projected into the tube containing the chloride of calcium, whilst part of the substance was often conducted undecomposed into the potash apparatus. Nevertheless the determination of the carbonic acid has several times been accomplished: from the data thus obtained, this yellow substance must be very rich in oxygen.
Chloride of Spiroil.
Chloride of spiroil may be obtained by decomposing hydrospiroilic acid by means of chlorine. In a suitable apparatus and without the application of heat, dry chlorine gas was passed over the anhydrous acid; evolution of muriatic acid immediately commenced: if the chlorine be evolved but slowly, only a slight elevation of temperature takes place. Chlorine is to be passed through this solution so long as fumes of muriatic acid are evolved: the hydrospiroilic acid is entirely converted into a white crystalline mass.
If however the oil is become solid, the chlorine apparatus must be moved, and the chloride of spiroil which has been formed must be sublimed by the lowest possible heat.
The most beautiful crystalline plates of a dazzling whiteness are obtained, which melt at a very low heat, and, as has been before remarked, may easily be sublimed.
​If chloride of spiroil be briskly heated, the melted mass gradually becomes darker, and a slight carbonaceous residue remains.
No other products besides muriatic acid and chloride of spiroil are formed.
Pure chloride of spiroil possesses a peculiar and somewhat aromatic odour, which nevertheless has much similarity to the smell of diluted prussic acid. Its boiling point does not appear to exceed that of water. It is inflammable, and burns with a greenish sooty flame.
It is quite insoluble in water.
When it is boiled with water it evaporates entirely; by this operation not the slightest trace of muriatic acid is formed. Neither dry nor moist air has any action on it. Chloride of spiroil is easily soluble in æther and alcohol.
The alcoholic solution gives with acetate of copper a greenish yellow precipitate; salts of lead are precipitated yellow. Baryta water immediately separates chloride of spiroil from the alcoholic solution, and uniting with it a yellow precipitate falls.
Chloride of spiroil forms yellow, neutral, difficultly soluble compounds with the alkalies. The salts of iron are also coloured blueish black by the same.
In the combinations of chloride of spiroil with the metallic oxides and the alkalies, it appears to combine unaltered, as it may again be obtained unaltered when these compounds are decomposed by an acid.
Nitrate of silver causes a scarcely perceptible milkiness in the filtered solutions of the alkaline compounds which have been decomposed by nitric acid. 0·780 grm. of chloride of spiroil treated in the above-mentioned way gave 0·09 grm. chloride of silver, therefore scarcely 0·02 grm. chlorine. This small amount of chlorine was no doubt due to the presence of muriatic acid, as from 0·628 grm. hydrospiroilic acid 0·795 grm. of chloride of spiroil was obtained; therefore at least 0·157 grm. chlorine must have been taken up.
If chloride of spiroil be melted with potassium by the application of a very gentle heat, violent evolution of heat and light suddenly takes place. A portion of the chloride of spiroil is decomposed thereby; carbon is deposited, whilst another portion unites with the potash which has been formed. If the remaining mass be dissolved in water, and the solution decomposed by nitric acid, pure chloride of spiroil is precipitated. If this same fluid be filtered, nitrate of silver gives a large precipitate of chloride of silver. If the neutral solution of the chlorospiroilide be slowly evaporated, yellow tasteless crystals are obtained which are insoluble in alcohol. If these crystals be heated in a platinum crucible, heat and fight are evolved long before the crucible is red hot. The mass blackens, and by the continued application of heat is converted into pure chloride of potassium, in the aqueous solution of which not the ​slightest alkaline reaction is visible. All these experiments seem to confirm the above-mentioned view, that chloride of spiroil combines without decomposition with the bases of salts.
The question may here be asked, whether the acid properties of the chloride of spiroil arise from chlorine, and whether such a chloracid (in the same way as oxyacids) could combine with them?
Till now no such combinations were known, and therefore perhaps it might be simpler to state that when chloride of spiroil is brought together with a metallic oxide, 4 eqs. of a metallic chloride and 1 of a spiroilate are formed. If an acid be added to the solution of these salts, chloride of spiroil is again thrown down and a corresponding metallic salt formed. In the same manner one may imagine double combinations, consisting of a metallic chloride and a salt of a bromacid, from which on the addition of another acid chloride of bromine might be separated.
0.327 grm. of fused chloride of spiroil yielded
| 0·593 grm. carbonic acid | = 162.94 carbon. |
| 0·099 water | = 10.98 hydrogen. |
0.327 grm. chloride of spiroil dissolved in potash entirely free from chlorine, the solution evaporated, and the dry residue heated in a platinum crucible yielded, after the mass which had been heated was dissolved in water and saturated with nitric acid, 0.306 fused chloride of silver = .754 chlorine.
| Carbon | 162.94 | 49.83 |
| Hydrogen | 10.98 | 3.35 |
| Oxygen | 77.68 | 23.77 |
| Chlorine | 75.40 | 23.05 |
| | 327.00 | 100.00 |
1 eq. of chloride of spiroil therefore consists of
| 12 | eqs. carbon | 73.56 | 50.38 |
| 5 | — hydrogen | 5.00 | 3.42 |
| 4 | — oxygen | 32.00 | 19.36 |
| 1 | — chlorine | 35.47 | 26.84 |
| | | 146.03 | 100.00 |
It has been stated that 0.628 grm. hydrospiroilic acid contained 0.795 chloride of spiroil. According to the established eq. 111.56 hydrospiroil should yield 146.03 chloride of spiroil:
11.56 : 146.03 = 0.628 : 0.790.
Bromide of Spiroil.
Bromide of spiroil is easiest obtained by pouring bromine upon hydrospiroilic acid in a deep glass: hydrobromic acid is immediately evolved, the mixture becomes perceptibly warm, and at last solidifies into a greyish white crystalline mass. Bromide of spiroil may also be easily ​obtained by agitating the aqueous solution of hydrospiroilic acid with solution of bromine; it is immediately precipitated in white flocks: the supernatant liquid is colourless, has no smell, and contains hydrobromic acid. In order to free the bromide of spiroil from excess of bromine and hydrospiroil, it must be kept melted in a water-bath so long as acid fumes are given off. Bromide of spiroil is exactly similar to the chloride of spiroil in all its properties; it is quite insoluble in water, and is easily soluble in aether and alcohol. By the spontaneous evaporation of the alcoholic solution it is obtained crystallized; bromide of spiroil melts at a rather higher temperature than the chloride, and like the latter may also be entirely sublimed: when boiled with water it evaporates unaltered. Its behaviour, with regard to the saline bases, is exactly the same as chloride of spiroil, but the alkaline salts are more difficultly soluble: 0.480 grm. bromide of spiroil dissolved in potash and decomposed by nitric acid yielded only 0.02 bromide of silver.
I. 0.510 grm. fused bromide of spiroil yielded
| 0.690 | carbonic acid | = 190.78 carbon. |
| 0.510 | water | = 13.11 hydrogen. |
Further, by solution as above-mentioned in pure caustic potash, and combustion of the compound formed, 0.510 grm. bromide of spiroil became 0.485 bromide of silver = to about 0·2036 bromine.
| Carbon | 190.78 | | 37.41 |
| Hydrogen | 13.11 | | 2.57 |
| Oxygen | 192.41 | | 20.02 |
| Bromine | 203.60 | | 40.00 |
| 510.00? | 510.00? | 510.00? | 100.00 |
II. 0·325 grm. bromide of spiroil yielded
| 0.457 | grm. carbonic acid | = | 126.00 | carbon. |
| 0.081 | ...... water | = | 8.99 | hydrogen. |
III. 0·305 grm. bromide of spiroil yielded
| 0.409 | grm. carbonic acid | = | 113.00 | carbon. |
| 0.071 | ...... water | = | 7.88 | hydrogen. |
If the proportions of bromine in I. be taken, we obtain in 100 parts
I.
| Carbon | 38.77 | 37.05 |
| Hydrogen | 2.72 | 2.55 |
| Oxygen | 18.51 | 20.40 |
| Bromine | 40.00 | 40.00 |
| | 100.00 | 100.00 |
| 12 | eqs. carbon | 73.56 | 38.80 |
| 5 | — hydrogen | 5.00 | 2.62 |
| 4 | — oxygen | 32.00 | 17.10 |
| 1 | — bromine | 78.39 | 41.48 |
| 1 bromide of spiroil = | 1 bromide of spiroil = | 188.95 | 100.00 |
Iodide of Spiroil.
Hydrospiroilic acid dissolves iodine in great quantities, and forms with it a brownish black fluid; the formation of hydriodic acid is however not perceptible. Iodide of spiroil may be obtained by distilling chloride or bromide of spiroil with iodide of potassium; even by rubbing these substances together decomposition commences, and by the application of heat iodide of spiroil sublimes: it is solid, of a dark brown colour, easily fusible, and shows in general the same properties with regard to solubility in water, æther and alcohol, and its relations to saline bases, as chloride and bromide of spiroil.