Many syrups which are rarely required, and which are apt to decompose on keeping, may be prepared from the liquors, provided the dispenser assures himself that the finished product is similar to the official one, and does not contain added preservatives which may interfere with other ingredients in dispensing. Such liquors are now easily obtainable.

Mist. Ammoniaci. - A 1-to-7 preparation is made by taking 1 ounce of picked white tears of the gum resin, powdering, rubbing down with 1 1/2 ounce of water, and adding syrup of tolu to 4 ounces. In dispensing add 1 part of this to 7 parts of water.

Mist. Cretae. - The powders for chalk mixture may be kept ready mixed, so that 3/4 ounce and 15 grains of the powder with 7 1/2 ounces of cinnamon-water will make mistura cretae.

Mist. Ferri Co. - Use only picked pieces of myrrh for this- good rich ambery and oily like pieces- and powder fresh. Proceed as directed in the B.P., but omit the ferrous sulphate, which add in proper proportion to the emulsive mixture when it is dispensed.

Spt.AEtheris Nitrosi. - Concentrated preparations of nitrous ether are more prone to decomposition than the B.P. spirit when exposed to the air and light. If, therefore, concentrated preparations are employed at the dispensing-counter, they should be used in the diluted state only, and the greatest care should be taken to ensure their preservation by keeping in small, well-stoppered and inverted bottles in a cool, dark place. Amber-glass bottles are best.

Syr. Croci. - A concentrated infusion (1 to 4) saturated with chloroform keeps much better than the syrup.

Syr. Ferri Iodidi. - This is now largely prepared from the liquor (1 to 7), which is kept permanently bright and free from oxidation by means of a trace of hypophosphorous acid.

Syr. Ferri Phosph. - This darkens very much on keeping, but a concentrated solution of pure iron in phosphoric acid eight times the strength of the syrup changes very slowly, especially if kept in bottles quite full. This may be diluted with simple syrup as required.

Syr. Ferri Phosph. c Quin. et Strych. - This also darkens rapidly, but if the ferrous phosphate be omitted and the syrup made up to 7 parts instead of 8, and filtered through paper, a brilliant syrup is obtained which keeps indefinitely. Seven parts of this should be mixed with 1 part of liquor ferri phosph. as required.

Syr. Rhceados and Syr. Violae, unless in frequent demand, are much better made from liquors.

There are many other preparations which may be conveniently kept in the concentrated or 'liquor' form. Some manufacturers have made this class of preparations a speciality. It would be out of place to speak of their products here, but it may be said that if the dispenser is seldom called upon for certain preparations, such as syrups, which on keeping undergo apparent alteration, these may be kept in stock in the permanent ' liquor' form, to be diluted as required. The dispenser should, of course, satisfy himself that the finished product answers to the official requirements.