This simple experiment serves to prove, with certainty, that cod-liver oil contains oxide of propyl. The propylamin thus obtained possesses all the properties of that obtained from the pickle of herrings, or ergot of rye.
Cod-liver oil by saponification with potash, is separated into oleic and margaric acids, and oxide of propyl; and with oxide {243} of lead, into oleic and margaric acids, and propylic acid—a higher result of the oxidation of propyl—and gives by either process of saponification no hydrate of the oxide of glycyl. The glycyl (C6 H3) is in this oil replaced by propyl (C6 H7). Only in cod-liver oil are the conditions offered for the formation of propylamin (N H2 C6 H7), by the presence of ammonia, as all the fat oils employed in medicine are free from this substance; therefore none of these oils can be substituted for cod-liver oil.
[Should this research of Winckler, as to the existence of the hydrate of the oxide of propyl in combination with the fatty acids in cod-liver oil, be confirmed, it will establish an important fact in chemistry, and may explain the therapeutic action of that remedy which has heretofore puzzled both chemists and physicians. The combinations of the radical propyl have been previously only known as artificial productions; therefore Wincklers’s experiments, if true, show that they exist in nature, or, in other words, that they are educts, and not products, from cod-liver oil. Moreover, the presence of oxide of propyl, and the absence of oxide of glycyl in cod-liver oil, will enable chemists to distinguish by tests, with certainty, this oil from other fatty oils.]—Annals of Pharmacy, June, 1852.
GUARANA. COMMUNICATED BY D. RITCHIE, SURGEON, R. N.
A medicinal substance named guaraná was presented to me about two years ago by a Brazilian. The virtues which he asserted that it possessed induced me to employ it as a remedy in several troublesome and obstinate cases of disease. The consequent benefit was so decided, that I was convinced of the {244} great value it possessed as a remedial agent. This conviction, with the belief that it was still unknown, impelled me to bring the subject under the notice of the profession in this country. A short account of it was therefore transmitted to the editor of the “Edinburgh Monthly Medical Journal,” who forthwith submitted it to Professor Christison. To the kindness and extensive acquirements of this gentleman I am indebted for the information, that the subject had already engaged the attention, of the brothers Martius in Germany, and several French writers. It was a matter of satisfaction to me to find that the opinions I had expressed regarding the great prospective importance of this substance were fully borne out by all those who have diligently examined it.
As a knowledge of the properties and uses of guaraná appears to be still little diffused in this country, I shall consider that I am performing an acceptable service to the medical profession in placing before it an abstract of the more important facts that are known regarding this substance. Public attention was first directed to it by M. Gassicourt in 1817, (Journal de Pharmac., tom. iii., p. 259); but the merit of discovering the source whence it is derived, and of furnishing a more complete description of it, belongs to Von Martius, in the year 1826, (Reise, vol. ii., p. 1061, et seq.)
The term guaraná is derived from the name of a tribe of Indians, who are dispersed between the rivers Parama and Uruguay, by whom it is very commonly used as a condiment or medicine. It is, however, more extensively prepared for commercial purposes by the Mauhés, an Indian tribe in the province of Tapajoz. It is, according to Martius, prepared from the seeds of the Paullinia sorbilis, a species belonging to the natural family Sapindaceæ. The characters of the species are:—Glabra, caule erecto angulato, foliis pinnatis bijugis, foliolis oblongis, remote sinuato-obtuse-dentatis, lateralibus basi rotundatis, extimo basi cuneato, petiolo nudo angnlato, racemis pubescentibus·erectis, capsulis pyriformibus apteris rostratis, valvulis intus villosis. The seeds, which ripen in the month of {245} October and November, are collected, taken out of their capsules, and exposed to the sun, so as to dry the arillus in which they are enveloped, that it may be more readily rubbed off by the fingers. They are now thrown upon a stone, or into a stone mortar, and reduced to powder, to which a little water is added, or which is exposed to the night dew, and then formed by kneading into a dough. In this condition it is mixed with a few of the seeds entire or contused, and divided into masses, weighing each about a pound, which are rolled into cylindrical or spherical forms. These are dried by the sun or by the fire, and become so hard as to be broken with difficulty. Their surface is uneven, brown, or sometimes black, from the smoke to which they have been subjected; their fractured surface is conchoidal, unequal, and resinoid; color reddish brown, resembling chocolate. This is the guaraná, and in this condition, or reduced to powder, it is kept for use or carried to market. The Museum of the Edinburgh College of Physicians contains a specimen of it in each of these forms. As it is liable to be adulterated with cocoa or mandioca flour, it is of great importance to be aware that the genuine article is distinguished by its greater hardness and density, and that, when powdered, it does not assume a white color, but a grayish-red tint.
A chemical analysis of this substance was first made by Theodore Martius, in 1826, (Buchner’s Repert. de Pharm. xxxi., 1829, p. 370). He found it to consist of a matter (tannin?) which iron precipitated green, resin, a fat green oil, gum, starch, vegetable fibre, and a white, bitter, crystalline product, to which the efficacy of the medicine was principally owing, and which he called guaranine. This he believed to be distinct from, but allied to, theine and caffeine, and to possess the following elementary constituents:—C8, H10, O2, N4.
Another very careful analysis of guaraná was made in the year 1840, by MM. Berthemot and Dechastélus, (Journal de Pharmacie, tom. xxvi., p. 518, et seq.), which varies in some degree from the preceding. They found the matter, which {246} was considered to be resin by Martius, a combination of tannin with guaranine, existing in a form insoluble in water or ether. They also determined the perfect identity of the crystalline matter with caffeine. It is found to exist in a much larger proportion in the fruits of the Paullinia than in any of the plants from which it has hitherto been extracted. Alcohol is the only agent which completely removes it from the guaraná. To this solution the addition of lime or hydrated oxide of lead gives, on the one hand, the insoluble tannates, and on the other, the crystalline matter.