Coffee And Its Medicinal Properties
( Originally Published 1900 )
THE stimulating and refreshing action of coffee is mainly due to the presence of caffeine and a volatile oil. Caffeine belongs to the group of substances known as alkaloids, which as a class have usually a bitter taste and are only slightly soluble in water. Amongst other well-known alkaloids are cocaine, the active principle obtained from coca leaves ; morphine, codeine, and narcotine, the essential constituents of opium ; quinine and cinchonine, to which the bark of cinchona owes its properties theobromine contained in cacao. Theine, the alkaloid of tea, is practically identical with caffeine, and both are very similar to theobromine. Paraguay tea, or maté, and kola nuts contain caffeine.
The quantity of caffeine present varies greatly in different species of coffee. It is never very large in amount, slightly under 20 per cent. of the dry seeds being the highest recorded. Analyses of Arabian coffee show a range of between 0.7 and P6 per cent., whilst Liberian coffee varies from about 10 to P5 per cent. The wild Sierra Leone coffee (Coffee stenophylla) contains about P5 per cent. Four species of coffee, natives of Madagascar or of the neighbouring islands, do not contain any caffeine.
Though it is impossible to give one definite analysis, the usually accepted standard is one issued by a French savant, M. Payen ; it is as follows
Fat 10 to 13 parts
The effect of roasting is to change many of these chemical constituents. What takes place is described by Messrs. A. W. and M. W. Blyth in their book on Foods, their Composition and Analysis, as follows
” The effect of roasting is to drive off a large quantity of water, to volatise a small quantity of theine, to change a portion of the sugar into caramel, to rupture the cell-layers containing fat and albumen, and to swell the berry by the extrication of gases, consisting mainly of carbon dioxide. There is also developed a fragrant aromatic substance, a single drop of which is sufficient to scent a large room with the peculiar coffee odour ; the best temperature for the production of this aroma is 210° C. That during roasting there is an actual loss of theine, is easily proved by holding a glass plate over the heated berries ; in a very little time crystals of theine condense. Tenneck found in unroasted coffee 75 per cent., and in the same roasted, 42 per cent. theine.”
The principal changes which take place during roasting appears from the following tables to be, that the quantity of sugar is largely reduced, while there is a considerable increase in the extractive matter, some of which is of a nitrogenous character.
Ash 3.97 5.17
It is extremely unfortunate that it is so little known what a valuable substance coffee is, and that, too, in such different ways. No doubt its chief feature is that it is a stimulant, it acts directly upon the heart, increases the frequency of the pulse, and sustains the strength under prolonged and severe muscular exertion. It is an antisoporific, and is useful in narcotic poisoning. For this reason it is frequently used by those who have to study until late hours ; indeed in its early days it was largely used by monks of many nationalities to overcome drowsiness during long nocturnal vigils. It is further said to be valuable in cases of spasmodic asthma, and to have been successfully used in cases of hysteria. Fresh roasted coffee, freshly ground, is also a valuable disinfectant, and may be most advantageously used in a sick room ; by sprinkling some on a chafing dish, foul and noxious exhalations are almost immediately neutralized or dispelled. It is a well-known fact that those engaged in the roasting of coffee are less liable to incur disease in times of epidemic. It is also on record, that during a virulent outbreak of smallpox in the East End of London, there was not a single case in any of the small houses that abutted upon a large coffee-roasting establishment, though there were many cases in the adjoining streets. The medical officer of health attributed this immunity solely to the fumes of the roasting penetrating through the open windows of the factory to the houses surrounding.
The following facts are reported by the British Consul in Colombia In the year 1906, Dr. L. Restrepo, of Meddellin, the capital of the department of Antioquia, in the Republic of Colombia, South America, convinced himself that the husk of coffee was of great utility in the treatment of several diseases, and that in malaria it sometimes succeeded where quinine had failed. Having regard, on the one hand, to the immense importance of such a discovery, if it were verified, and, on the other hand, to the remoteness of the Republic of Colombia from the acknowledged centres of medical activity, the German legation at Bogota, the capital of the country, forwarded copious details of Dr. Restrepo's observations to the proper authorities in Berlin—of course, without anything of the nature of official endorsement.
Dr. Restrepo at first used an infusion made with 45 grammes of crushed coffee (in the husk), and 400 grammes of water. This was boiled for five minutes, strained and taken in one day in six doses. With this medicine he successfully treated five patients, of whom three suffered respectively from intermittent malarial fever, chronic malarial fever, and pernicious fever, and two suffered from enteric colic or chronic dysentery of malarial origin. Before taking this infusion, patients had all been declared fatal cases, given up by well-known doctors of good repute. Restrepo afterwards made this infusion with 30 grammes of coffee husk alone in place of 45 grammes of crushed coffee, the other details of preparation and the dose being as before. With this he says he treated hundreds of cases, not one patient died, and a cure resulted in every instance.
An eminent Vienna oculist in the last century has held that the vapour from pure, hot, freshly-made coffee is beneficial to the eyes, further that he has traced many cases of affections of the sight to the constant use of chicory, and even to preparations of mixtures of coffee and chicory. A remarkable remedy for rheumatism and gout is said to be as follows :—A pint of hot, strong, black coffee, which must be perfectly pure, and seasoned with a teaspoonful of pure black pepper, thoroughly mixed before drinking, and the preparation taken just before retiring.
At various times paragraphs have appeared in the newspapers stating that the constant use of coffee is injurious. No real facts in support of this have been produced, in fact the action imparted to the nervous system is both natural and healthy, and it has been proved that habitual coffee-drinkers generally enjoy good health and spirits, some of the longest-lived people having used coffee continually from their earliest infancy, without experiencing any inconvenience.
Like everything else, no doubt, coffee may be taken to excess. The amount of caffeine contained in 3 lbs., if extracted and taken pure, would be sufficient to kill a man. The operation of caffeine upon a number of selected healthy persons has been tried with very varying results. Some were scarcely affected, others from the same dose suffered from a full, irregular pulse, trembling limbs, headache, flashes before the eyes, sleeplessness, a sort of intoxication, with an unfitness for all physical and mental labour. The moral is to be moderate in the use of coffee, it being then beneficial, and to avoid excess. It is stated of Voltaire that being told by his physician that " coffee was a slow poison," replied : Yes, I know it is a slow poison ; it has been poisoning me for over seventy years " ; while of President Kruger, who lived to be over eighty, it was said that he had a jug of coffee always on his table.