Which, though not generally recognized, are occasionally ordered.
Many plants yield their virtues more fully to water than to alcohol or any other menstruum. There is, however, a great practical difficulty as regards these preparations, and that is, they will not keep; and accordingly, it is still a desideratum that some method should be devised whereby they can be preserved from decomposition. It is probable that the addition of a certain proportion of alcohol will effect this, and the subject is suggested as a very suitable one for experiment. In the meantime, these preparations must be made fresh when required. They are prepared as follows: -
1. Gold Infusions. - Reduce the drug to a coarse powder, pack it in a percolator, precisely as directed for tincture-making, then let 10 fluid ounces of distilled water for every 1 ounce of dry material be passed through the percolator in the ordinary way.
2. Hot Infusions. - Prepare the medicinal substance as above, and tie it loosely in a bag of clear, well-washed book-muslin, and then pour 10 fluid ounces of boiling distilled water for every 1 ounce of dry material into an infusion pot; place the bag containing the substance on the diaphragm, cover over the vessel, and keep it in a warm place for an hour, when the fluid may be poured off, and that retained in the bag squeezed out, and the two mixed together and filtered.
3. Decoctions. - Prepare the drug as before, put it into a porcelain dish, then pour 10 fluid ounces of distilled water for every 1 ounce of dry material over it; place the dish over a water-bath, raise it to 200° F., and keep it at that temperature for half an hour, when the fluid may be decanted and filtered.
If attenuations of these are required, they must be made as soon as the preparations are ready; pure distilled water being used for the 1st decimal and centesimal attenuations, dilute alcohol for the 3rd decimal, and rectified spirit for the 2nd centesimal and upwards.