Having on hand a small sample of the leaves procured from New Berue during the winter of 1883, it seemed desirable to make an examination of them, to decide, if possible, the presence of any alkaloid or other principle which would make the decoction useful as a beverage. The usual treatment with magnesium oxide, exhaustion with water, separation by means of chloroform, and subsequent purification was adhered to, resulting in obtaining a small amount of a white substance slightly soluble in water, more so in alcohol, and easily soluble in chloroform, which gave distinctly the tests for caffeine, especially the murexide reaction, and very closely resembled a specimen of pure caffeine from Powers & Weightman.
This caffeine formed .32 per cent. of the dried leaves. Later on, in May, a much larger supply of the same leaves was gotten from the neighborhood of Wilmington. A more thorough examination of them was then made, with the following results:
| Water in air-dried samples | 13.19 |
| Extracted by water | 26.55 |
| Tannin | 7.39 |
| Caffeine | .27 |
| Nitrogen (on combustion) | .73 |
| Ash | 5.75 |
Maté or Brazilian holly (Ilex paraguayensis) belongs to the same genus. Its ash analysis, as made by Señor Arate, is given in the second column. The plant grows wild in Brazil, and is very largely used by the South Americans. It has, according to Peckolt (Pharm. J. Trans. (3) 14, 121-124; Abstract Jour. Chem. Soc., 1884, 479), been planted, and seems to succeed well, in the Cape of Good Hope, Spain, and Portugal. It is stated that six different species of Ilex are used in the preparation of this tea. Peckolt gives, in his analysis of the air-dried leaves, the percentage of caffeine as 0.639. The average percentage of analyses by different authors is about 1.3. I can find mention of only one other Ilex used as a substitute for tea. The analysis of this by Ryland and Brown is quoted in Blythe’s “Composition and Analysis of Foods” (p. 343). It is called the Ilex cassiva, is said to be used as a tea in Virginia, and the percentage of caffeine is given as 0.12. This is probably the same thing as the yopon, the analysis of which is given above, and the “cassiva” may be a misprint for “cassine.”
In a more recent paper Professor Venable reports additional analyses, which are interesting. He says:
Some years ago an analysis of the leaves of Ilex cassine was given in this journal.[4] In this analysis appeared the interesting fact that these leaves contained a small percentage of caffeine. During the winter of 1885-’86, at the request of some medical friends whose attention was drawn to the analysis, a more thorough examination was undertaken, not only of the leaves, but of the berries. It was thought advisable, at the same time, to examine the leaves and fruit of other representatives of the Ilex family in this State—Ilex opaca and Ilex dahoon. This was primarily a search after alkaloids, and not intended as a complete chemical examination. As no alkaloids were found other than the caffeine already mentioned, no account of the work was published, and the results have been hidden away in my note books ever since. Thinking, however, that even negative results are often of some value and that the partial analysis might be of aid to others, I offer this paper for publication in the journal of the society.
Besides the I. opaca, I. dahoon, I. cassine, according to Curtis there are in this State five additional species of this genus: I. decidua Walt. I. ambigua Chapman; I. verticillata Gray, I. glabra Gray, I. coriacea Chapm, but the examination was not extended to them. In searching for the alkaloids the directions of Dragendorff were first followed. The leaves (or crushed berries) were first digested at 40°-50° with dilute sulphuric acid. This extract was evaporated to a sirupy consistence, the residue mixed with three or four times its bulk of alcohol, filtered after 24 hours’ standing, and washed with alcohol. The alcohol was then distilled off from the filtrate, the watery residue was diluted with water and filtered. Petroleum-ether, benzol, and chloroform were successively used to extract the alkaloidal principles, if any were present in the acid liquid. Then, after rendering alkaline with ammonia, the liquid was again extracted with the solvents mentioned.
As, even with water but slightly acidified with sulphuric acid, some risk of the destruction or change of the alkaloids was run during the long evaporation, a second method was made use of, as follows:
The leaves were digested for 10 hours with 70 per cent alcohol, the alcohol distilled off, and the residue treated with lead acetate and soda. The excess of lead was removed by means of sulphuretted hydrogen and the filtrate from this evaporated to a thin sirup. This was then treated with strong alcohol, filtered, and the excess of alcohol distilled off. Bismuth, potassium-iodide, and sulphuric acid were next used to precipitate any alkaloid present. The presence of albuminoid matter rendered it necessary to decompose this by means of soda, neutralized with dilute sulphuric acid, and reprecipitate with mercuric chloride. The solutions to which mercuric chloride had been added were allowed to stand several days. The results may be tabulated as follows:
| I. opaca, leaves | No alkaloid. |
| I. opaca, berries | No alkaloid. |
| I. dahoon, leaves | No alkaloid. |
| I. dahoon, berries | No alkaloid. |
| I. cassine, leaves | Caffeine. |
| I. cassine, berries | No alkaloid. |