‘“As the practice in preparing this oil is somewhat different from that of common olive oil, it may be useful to enter into some details on the subject. I have myself been present during the whole operation, and consequently speak from experience.
‘“In the end of March the countryman goes into the wood, where the fruits are shaken down from the trees and stripped of their husks on the spot. The green fleshy pericarp, which is good for nothing else, is greedily eaten by ruminating animals, such as camels, goats, sheep, and cows, but especially by the first two. Therefore, when the Arab goes into the woods to collect Argan nuts, he gladly takes with him his herds of the above animals, that they may eat their fill of the green husks whilst he and his family are collecting and shelling the nuts. The horse, the ass, and the mule, on the contrary, do not like this food. When a sufficient quantity of nuts are collected they are brought home, the hard wooden shell is cracked between stones, and the inner white kernels are carefully extracted. These are roasted or burnt like coffee on earthen, stone, or iron plates; in order that they may not be too much done, they are constantly stirred with a stick. When properly roasted they should be all over of a brown colour, but not charred on the outside. The smoke, which is disengaged during the process, has a very agreeable odour. As soon as the kernels have cooled, they are ground in a handmill into a thick meal, not unlike that of pounded almonds, only that it is of a brown colour, and the meal is put into a vessel in which the oil is separated, which is done by sprinkling the mass now and then with hot water, and keeping it constantly stirred and kneaded with the hand. This process is carried on until the mass becomes so hard that it can no longer be kneaded: the harder and firmer are the residuary coarse parts, the more completely is the oil extracted. At the last, cold water is sprinkled upon it, in order, as they say, to expel the last particles of the oil. During the operation the oil runs out at the sides, and is from time to time poured into a clean vessel. The main point to be attended to in order to extract the greatest quantity and the best quality of oil, is that it should be well kneaded, and that the proper proportion of hot water for the extraction of the oil should be used; it is always safer to be sparing of it than to be too profuse. The residuary mass, often as hard as a stone, is of a black-brown colour, and has a disagreeable bitter flavour. The oil itself, when it has settled, is clear, of a light brown colour, and has a rancid smell and flavour. When it is used without other preparations in cooking, it has a stimulating and pungent taste which is long felt on the gums. The vapour which arises when anything is fried in it, affects the lungs and occasions coughing. The common people use it generally without preparation; but in better houses it is the custom, in order to take off that pungency, to mix it previously with water, or to put a bit of bread into it and let it simmer before the fire.
‘“The wood, which is hard, tough, fine-grained, and of a yellow colour, is used in house carpentry, and for other purposes.”’
‘We have been at some pains to distribute the seeds of this plant, with which we have been liberally supplied, to various parts of the East Indies, and to such of our Colonies as appeared suited to the growth of this tree, in respect of climate, &c. It is impossible for seeds to be in better condition; and though the surrounding hard portion of the nut is as thick and solid as that of hickory, those which we ourselves sowed sprouted in less than a month from the time they were put in the ground. The young trees bore the rough treatment of the voyage in midwinter remarkably well; and it is easy to see that this is a plant of ready culture in favourable climates.
‘The value of the husks of the fruit as food for cattle, and the uses of the wood, are mentioned in the above extracts. The nature of the oil seems only to have been considered in relation to olive oil. But vegetable oils are now so much in demand, especially by Messrs. Price & Co., for their great candle-works at Vauxhall, as well as at Birkenhead, near Liverpool, that I was anxious to know the opinion of Mr. G. F. Wilson, the scientific director of those vast establishments, on the nature of Argan oil. Some seeds were consequently communicated to that gentleman, and he lost no time in experimenting upon them, and assuring me that “they contain a large percentage of a very fine oil. We have tried it in several ways, in each case with a favourable result. Some is now being exposed to a severe test, to show how the air acts upon it: I have, however, little fear but that it will answer. Our city friends are inquiring for us the best means of getting a ton or two of the nuts for experiments on a large scale. The only unfavourable point I see is the small weight of kernel to that of hard shell:—
| 6 Nuts gave | — | kernel 30 grains |
| „ „ | hard shell 350 grains | |
| „ „ | outer husk 193 grains. |
The hard shell probably should be sent home with the seed when the kernels are required to yield a sweet oil; for unless prepared with great care, hardly to be expected in a wild country, the oil would not be nearly so sweet if sent home expressed, instead of in its kernel and shell. Perhaps if the kernel is pounded and rammed tightly into casks, we might obtain sweet oil without great waste in freight.”
‘In a botanical point of view this plant is scarcely of less interest than in an economical. It has had the hard fate, often the consequence of being with difficulty procured, to be much misunderstood, and, except by Schousboe, to be imperfectly described; and references are given in works to plants as being identical which have no relationship with it; or to descriptions which, if the same, exhibit little or no resemblance.
‘The first botanist who appears to have noticed this plant is Linnæus, who, in the Hortus Cliffortianus, in 1737, described it, from dried specimens, under the name of Sideroxylon spinosum. “From Clifford’s Herbarium,” observes Mr. Dryander, “now in the possession of Sir Joseph Banks, the Argan was taken up by Linné in his Hortus Cliffortianus; though most of the synonyms are wrong, and consequently the locus natalis (utraque India) which is deduced from them. The specimen in Linné’s Herbarium, under the name of Sideroxylon spinosum, is without flowers, and it is impossible to tell you with any certainty what it is. Clifford’s Herbarium is therefore the only authority by which this species can be ascertained.” Linnæus’s Rhamnus siculus, in the Appendix to the third volume of the twelfth edition of the Systema Naturæ, is, we are assured by Mr. Dryander, “the Argan, or Olive-tree of Marocco (see Höst’s ‘Efterretninger om Marokos,’ p. 284), as appears from the specimen in Linné’s Herbarium, which has a ticket affixed, with the name of Argan of Marocco, and which I have also compared with specimens in Sir Joseph Banks’s Herbarium from Marocco.” The description, too, of Linnæus is very correct. He errs only in considering the plant to be the same as the Rhamnus Siculus pentaphyllos of Boccone (Rhus pentaphyllum, Desf.), which has folia quinata, which latter he introduces into the specific character, but not into the description; and he erroneously followed Boccone in giving Sicily as the native country in addition to Africa, and in adopting the specific name Siculus.
‘In the Species Plantarum of Linnæus, Malabar alone is mentioned as the native country of the Sideroxylon spinosum. Nevertheless, with the exception of Willdenow, who rejects it altogether as “planta valde dubia, forte nullibi obvia,” most of the older authors adopt this name for the Argan of Marocco. Under it, it appears in the first edition of Hortus Kewensis, with the reference to Species Plantarum of Linnæus, and to Commelyn, Hortus Amstelod. tab. 83, where, however, nothing is said of its native country, further than may be surmised by the name adopted from Breynius’s “Lycio similis frutex Indicus spinosus, Buxi folio” (which, as already observed, Willdenow considered to be his Flacourtia sepiaria, from India), and of which the flowers and fruit were unknown to the author. If this were the Argan, it was in cultivation in Holland as early as 1697. At a period not much later, viz. in 1711, according to the Hortus Kewensis, it was introduced into England: “Cult. 1711, by the Duchess of Beaufort, Br. Mus. H.S. 141, fol. 39.” It is indicated as a stove-plant.