along its edge for more than a third of its length from the apex; hence the raphe passes downwards to the rounded end of the seed, where a scar marks the chalaza. From this, a dozen or more ramifying veins run up the brown skin towards the pointed end. After an almond has been macerated in warm water, the skin is easily removed, bringing with it the closely attached translucent inner membrane or endopleura. As the seed is without albumen, the whole mass within the testa consists of embryo. This is formed of a pair of plano-convex cotyledons, within which lie the flat leafy plumule and thick radicle, the latter slightly projecting from the pointed or basal end of the seed. Almonds have a bland, sweet, nutty flavour. When triturated with water, they afford a pure white, milk-like emulsion of agreeable taste. Varieties-The different sorts of almond vary in form and size, and more particularly in the firmness of the shell. This in some varieties is tender and easily broken in the hand, in others so hard as to require a hammer to fracture it. The form and size of the kernel likewise exhibit some variation. The most esteemed are those of Malaga, known in trade as Jordan Almonds. They are usually imported without the shell, and differ from all other sorts in their oblong form and large size. The other kinds of sweet almonds known in the London market are distinguished in the order of value as Valencia, Sicily, and Barbary1 Microscopic Structure-Three different parts are to be distinguished in the brown coat of an almond. First, a layer of very large (as much as mm. in diameter) irregular cells, to which the scurfy surface is due. If these brittle cells are boiled with caustic soda, they make a brilliant object for microscopic examination in polarized light. The two inner layers of the skin are made up of much smaller cells, traversed by small fibro-vascular bundles. The brown coat assumes a bluish hue on addition of perchloride of iron, owing to the presence of tannic matter. The cotyledons consist of thin-walled parenchyme, fibro-vascular bundles being not decidedly developed. This tissue is loaded with granular albuminous matter, some of which exhibits a crystalloid aspect, as may be ascertained in polarized light. Starch is altogether wanting in almonds. A Chemical Composition-The sweet almond contains fixed oil extractable by boiling ether to the extent of 50 to 55 per cent. produce of 50 per cent. by the hydraulic press is by no means uncommon. The oil (Oleum Amygdala) is a thin, light yellow fluid, of sp. gr. 092, which does not solidify till cooled to between -10 and -20° C. When fresh, it has a mild nutty taste, but soon becomes rancid by exposure to the air; it is not, however, one of the drying oils. It consists almost wholly of the glycerin compound of Oleic Acid, CH3O2. Almonds easily yield to cold water a sugar tasting like honey, which reduces alkaline cupric tartrate even in the cold, and is therefore in part grape-sugar. Pelouze however (1855) obtained from almonds 10 Mandorlo in Sicilia, Palermo, 1874 (444 pages). 1 To be consulted for further information: Bianca, G. Mannale della Cultivazione del per cent. of cane-sugar. The amount of gum appears to be very small; Fleury (1865) found that the total amount of sugar, dextrin and mucilage was altogether only 6:29 per cent. If almonds are kept for several days in alcohol, crystals of asparagine (see article Rad. Althææ, p. 93) make their appearance, as shown by Henschen (1872), and by Portes (1876). The almond yields 37 per cent. of nitrogen, corresponding to about 24 per cent. of albuminoid matters. These have been elaborately examined by Robiquet (1837-38), Ortloff (1846), Bull (1849), and Ritthausen (1872). The experiments tend to show that there exist in the almond two different protein substances; Robiquet termed one of these bodies Synaptase, while others applied to it the name Emulsin. Commaille (1866) named the second albuminous substance Amandin; it is the Almond-legumin of Gmelin's Chemistry, the Conglutin of Ritthausen. Emulsin has not yet been freed from earthly phosphates which, when it is precipitated by alcohol from any aqueous solution, often amount to a third of its weight. Amandin may be precipitated from its aqueous solution by acetic acid. According to Ritthausen, these bodies are to be regarded as modifications of one and the same substance, namely vegetable casein. Blanched almonds comminuted yield, when slightly warmed with dilute potash, a small quantity of hydrocyanic acid and of ammonia; the former may be made manifest by means of Schönbein's test pointed out at p. 250. The ash of almonds, amounting to from 3 to nearly 5 per cent., consists chiefly of phosphates of potassium, magnesium and calcium. Production and Commerce-The quantity of almonds imported into the United Kingdom in 1872 was 70,270 cwt., valued at £204,592. Of this quantity, Morocco supplied 33,500 cwt., and Spain with the Canary Islands 22,000 cwt., the remainder being made up by Italy, Portugal, France, and other countries. The imports into the United Kingdom in 1876 were 77,169 cwt., valued at £244,078. Almonds are largely shipped from the Persian Gulf: in the year 1872-73, there were imported thence into Bombay, 15,878 cwt., besides 3,049 cwt. from other countries.3 Uses Sweet almonds may be used for the extraction of almond oil, yet they are but rarely so employed (at least in England) on account of the inferior value of the residual cake. The only other use of the sweet almond in medicine is for making the emulsion called Mistura Amygdala. AMYGDALE AMARÆ. Bitter Almonds; F. Amandes amères; G. Bittere Mandeln. Botanical Origin-Prunus Amygdalus Baillon var. a. amara (Amygdalus communis L. var. a. amara DC.). The Bitter Almond tree is not distinguished from the sweet by any permanent botanical character, and its area of growth appears to be the same (see p. 244). 1 Die Eiweisskörper der Getreidearten, Hülsenfrüchte und Oelsamen, Bonn, 1872. 199. 2 Gmelin, Chemistry, xviii. (1871) 452. 3 Statement of the Trade and Navigation of Bombay for 1872-73, pt. ii. 31. History (See also preceding article.) Bitter almonds and their poisonous properties were well known in the antiquity, and used medicinally during the middle ages. Valerius Cordus prescribed them as an ingredient of trochisci.' As early as the beginning of the present century, it was shown by the experiments of Bohm, a pharmaceutical assistant of Berlin, that the aqueous distillate of bitter almonds contains hydrocyanic acid and a peculiar oil which cannot be obtained from sweet almonds. It was then inferred that hydrocyanic acid itself might be poisonous, a fact which, strange to say, had not been noticed by Scheele, when he discovered that acid in 1782, as obtained by distilling potassium ferrocyanate with sulphuric acid. The dangerous action of hydrocyanic was then ascertained in 1802 and 1803 by Schaub and Schrader.2 3 Description-Bitter almonds agree in outward appearance, form, and structure with sweet almonds; they exist under several varieties, but there is none so far as we know that in size and form resembles the long sweet almond of Malaga. In general, bitter almonds are of smaller size than sweet. Triturated with water, they afford the same white emulsion as sweet almonds, but it has a strong odour of hydrocyanic acid and a very bitter taste. Varieties-These are distinguished in their order of goodness, as French, Sicilian, and Barbary. Microscopic Structure-In this respect, no difference between sweet and bitter almonds can be pointed out. If thin slices of the latter are deprived of fat oil by means of benzol, and then kept for some years in glycerin, an abundance of crystals is slowly formed, of what we suppose to be amygdalin. Chemical Composition-Bitter almonds, when comminuted and mixed with water, immediately evolve the odour of bitter almond oil. The more generally diffused substances are the same in both kinds of almond, and the fixed oil in particular of the bitter almond is identical with that of the sweet. Bitter almonds however contain on an average a somewhat lower proportion of oil than the sweet. In one instance that has come to our knowledge in which 28 cwt. of bitter almonds were submitted to pressure, the yield of oil was at the rate of 436 per cent. Mr. Umney, director of the laboratory of Messrs. Herrings and Co., where large quantities of bitter almonds are submitted to powerful hydraulic pressure, gives 44-2 as the average percentage of oil obtained during the years 1871-2. Robiquet and Boutron-Charland in 1830 prepared from bitter almonds a crystalline substance, Amygdalin, and found that bitter almond oil and hydrocyanic acid can no longer be obtained from bitter almonds, the amygdalin of which has been removed by alcohol. Liebig and Wöhler in 1837 showed that it is solely the decomposition of this body (under conditions to be explained presently), that occasions the formation of 1 Dispensator., Paris, 1548. 336. 337. 343. 2 J. B. Richter, Neuere Gegenstände der Chymie, Breslau, xi. (1802) 65. J. B. Trommsdorffs Journ. d. Pharm. xi (Leipzig, 1803) 262. Preyer, Die Blausäure, Bonn, 1870. 3 Hence to avoid bitter almonds being used instead of sweet, the British Pharmacopaia directs that Jordan Almonds alone shall be employed for Confection of Almonds. the two compounds above named. Disregarding secondary products (ammonia and formic acid), the reaction takes place as represented in the following equation: C20 H27 NO11+3 OH2OH2 2 (C6H12O6) NCH CHO. Anhydrous Hydro- Bitter Almond This memorable investigation first brought under notice a body of the glucoside class, now so numerous. Amygdalin may be obtained crystallized when almonds deprived of their oil are boiled with alcohol of 84 to 94 per cent. The product amounts at most to 2 or 3 per cent. Amygdalin per se dissolves in 15 parts of water at 8-12° C., forming a neutral, bitter, inodorous liquid, quite destitute of poisonous properties. It would appear from the investigations of Portes (1877) that in young almonds, amygdalin is formed before the emulsin. When bitter almonds have been freed from amygdalin and fixed oil, cold water extracts from the residue chiefly emulsin and another albuminoid matter separable by acetic acid. The emulsin upon addition of alcohol falls down in thick flocks, which, after draining, form with cold water a slightly opalescent solution. This liquid added to an aqueous solution of amygdalin, renders it turbid, and developes in it bitter almond oil. The reaction takes place in the same manner, if the emulsin has not been previously purified by acetic acid and alcohol, or if an emulsion of sweet almonds used. But after boiling, an emulsion of almonds is no longer capable of decomposing amygdalin. What alteration the emulsin itself undergoes in this reaction, or whether it suffers any alteration at all, has not been clearly made out. The reaction does not appear to take place necessarily in atomic proportions; it does not cease until the emulsin has decomposed about three times its own weight of amygdalin, provided always that sufficient water is present to hold all the products in solution. The leaves of Prunus Lauro-cerasus L., the bark of P. Padus L., and the organs of many allied plants, also contain emulsin or a substance analogous to it, not yet isolated. In the seeds of various plants belonging to natural orders not botanically allied to the almond, as for example in those of mustard, hemp, and poppy, and even in yolk of egg, albuminous substances occur which are capable of acting upon amygdalin in the same manner. Boiling dilute hydrochloric acid induces the same decomposition, with the simultaneous production of formic acid. The distillation of bitter almonds is known to offer some difficulties on account of the large quantity present of albuminous substances, which give rise to bumping and frothing. Michael Pettenkofer (1861) has found that these inconveniences may be avoided by immersing 12 parts of powdered almonds in boiling water, whereby the albuminous matters are coagulated, whereas the amygdalin is dissolved. On then adding an emulsion of only 1 part of almonds (sweet or bitter), the emulsin contained in it will suffice to effect the required decomposition at a temperature not exceeding 40° C. In this manner, Pettenkofer obtained in some experiments performed with small quantities of almonds, as much as 0.9 per cent. of essential oil. In the case alluded to on the opposite page, in which 28 cwt. of almonds were treated, the yield of essential oil amounted to 0.87 per cent. From data obligingly furnished to us by Messrs. Herrings and Co. of London, who distill large quantities of almond cake, it appears that the yield of essential oil is very variable. The yearly averages as taken from the books of this firm, show that it may be as low as 074, or as high as 1.67 per cent., which, assuming 57 pounds of cake as equivalent to 100 pounds of almonds, would represent a percentage from the latter of 0.42 and 0.95 per cent. respectively. Mr. Umney explains this enormous variation as due in part to natural variableness in the different kinds of bitter almond, and in part to their admixture with sweet almonds. He also states that the action of the emulsin on the amygdalin when in contact with water, is extremely rapid, and that 200 pounds of almond marc are thoroughly exhausted by a distillation of only three hours. In the distillation, the hydrocyanic acid and bitter almond oil unite into an unstable compound. From this, the acid is gradually set free, and partly converted into cyanide of ammonium and formic acid. Supposing bitter almonds to contain 33 per cent. of Amygdalin, they must yield 0-2 per cent. of hydrocyanic acid. Pettenkofer obtained by experiment as much as 0.25 per cent., Feldhaus (1863) 0.17 per cent. Some manufacturers apply bitter almond oil deprived of hydrocyanic acid, but such purified oil is very prone to oxidation, unless carefully deprived of water by being shaken with fused chloride of calcium. The sp. gr. of the original oil is 1061-1065; that of the purified oil (according to Umney) 1049. The purification by the action of ferrous sulphate and lime, and re-distillation, as recommended by Maclagan (1853), occasions, we are informed, a loss of about 10 per cent. Bitter almond oil, CH(COH), being the aldehyde of benzoic acid, CH°(COOH), is easily converted in that acid by spontaneous or artificial oxidation. The oil boils at 180° C. and is a little soluble in water; 300 parts of water dissolve one part of the oil. There are a great number of plants which if crushed, moistened with water, and submitted to distillation, yield both bitter almond oil and hydrocyanic acid. In many instances the amount of hydrocyanic acid is so extremely small, that its presence can only be revealed by the most delicate test,-that of Schönbein.' Among plants capable of emitting hydrocyanic acid, probably always accompanied with bitter almond oil, the tribes Prunea and Pome of the rosaceous order may be particularly mentioned. The farinaceous rootstocks of the Bitter Cassava, Manihot utilissima, Pohl, of the order Euphorbiacea, the source of tapioca in Brazil, have long been known to yield hydrocyanic acid. A composite, Chardinia xeranthemoides Desf.,growing in the Caspian regions, has been shown by W. Eichler also to emit hydrocyanic acid. The same has been observed by the French in Gaboon with regard to the fruits of Ximenia americana L. of the order Olacinea, and the 1 Applied in the following manner :-Let bibulous paper be imbued with a fresh tincture of the wood or resin of guaiacum, and after drying, let it be moistened with a solution composed of one part of sulphate of copper in 2000 of water. Such paper moistened with water will assume an in tense blue coloration in the presence of hydrocyanic acid. 2 Bull. de la Soc. imp. des nat, de Moscou, XXXV. (1862) ii. 444. 3 Exposition Univers. de 1867.-Produits des Colonies Françaises, 92. |