should be regarded as a generic name, while Acacia is a specific name properly applied only to that kind of Gum Arabic used in medicine. The Gum Arabic from which Acacia is selected comes chiefly from Kordofan, down the Nile, in sacks, to Cairo, Alexandria or Trieste. In this original condition it is called Gum Arabic "in sorts," that is, unsorted or unseparated. The fragments are of all shades of color lighter than a very dark amber, and are contaminated with bark, dust, etc. At the three points mentioned the Gum Arabic is picked-women, children and cripples being employed in picking it, and at Trieste especially, the picking constitutes quite a large and important industry. This picking separates the fragments by color and by freedom from adhering bark, etc., into. about five grades usually, and these are called, technically, in commerce, "first picked," "second picked," "third picked," and so on, and these grades are then fitted for their special uses chiefly in the arts for "sizes" and "bodies" and in confectionery. The first and second picked are very nearly colorless, and only differ in color by a shade or two, but the second picked is not so free from adhering specks of bark. The first three or four of these grades come into the markets in cases containing about 136 kilogrammes or 300 pounds each. The other grades come in bags. Of these grades the first picked only should constitute the Acacia of the Pharmacopoeias, and to this grade only does the name Acacia and the above officinal description properly belong. It is, therefore, not "Gum Arabic," but is "Acacia," selected by picking as the best and purest part of Gum Arabic. It is true, however, that this grade is rarely bought for medicinal uses, the second and third picked, which are considerably cheaper, being generally used. If not seen together, few buyers can distinguish between "first picked" and "second picked," so that sellers by keeping the "first picked" out of their assortment are easily able to sell second for first, and so on down.

Other varieties of Gum Arabic come down the Nile which are well known in commerce, but the sources of which are not well determined. They are not distinguishable in appearance from the gum just mentioned, and go through all the process of picking exactly as do the other gums, and they appear in the markets together, and in "first hands," that is, in the pickers' or in the large importers" hands, the cases are seen side by side, but after leaving " first hands" the distinctions between these and true Gum Arabic are commonly lost. These gums are, however, of inferior quality, and are sold at a lower price. A few years ago the difference in price amounted to

20 to 25 p. c., but of late the true Gum Arabic has fallen somewhat in price, and now the difference is hardly greater than 10 p. c. These inferior gums have been variously called "Gum Sennaar," or in the market "Senare," "Ghezireh " and " Gedda," probably from the districts in which they are collected; the latter name being the most common, and now pretty generally applied to the whole class. of these inferior gums.

"First picked Arabic" and "First picked Gedda" are often undistinguishable even by experts, unless seen together and closely compared, and hence the cheaper is often substituted for the better and dearer gum, and still more frequently is mixed with it as an adulterant. The chief characteristic of these poorer gums is a sour smell, which, though easily recognized in the "sorts" or in the lower grades, is by no means easy in the first and second picked. Generally, however, by brushing off the surface gum from the top of a case, and plunging the hands down so as to bring up a double handful from near the middle of the case, the sour odor can be detected. But if 10 or 20 p. c. of the Gedda only is mixed with the true gum, it is almost impossible to detect it.

The inferiority of these gums is that they make a thinner and poorer mucilage than the true gum, and a mucilage which changes and sours sooner. The expression in the arts and in confectionery is that it "does not go as far,"-" does not make as fine a stock,” and causes loss by spoiling more easily. The inference drawn by the writer from these circumstances is that these gums come from districts which are subjected to showers, or to some form of dampness which is sufficient to start a slight fermentation in the gum itself. This hypothesis is strengthened by the circumstance that a bag of fine gum which accidentally gets wet, soon develops this sour smell, while others of the same lot will have the natural freedom from all smell, or have the very faint, clean, sweet smell.

The uses of Acacia in medicine require it in two forms, namely, in solution and in fine powder. The solution is used in various ways and for many purposes, and is officinal in the forms of a mucilage and a syrup. The mucilage contains 34 p. c. of Acacia, and the syrup about 8 p. c. The solutions do not keep well especially when there is any admixture of Gedda in the Acacia, or when there is the least quantity of old solution left to start the souring of the new, and therefore they should always be freshly made. To make a good solution promptly not only requires some skill, but also requires that the Acacia be in a proper condition. Taking the

Acacia in its officinal condition the solution of the fragments is a very slow process. If it be rubbed up in a mortar enough of it goes into fine powder to make the whole clog together, and then again the process is tedious and troublesome, whilst if fine powder be taken there will be still more difficulty and the loss of more time.

Many years ago the writer made a series of trials to determine the condition best adapted to making easy and rapid solution, and the result was that a granulated acacia in the form of a coarse powder free from any fine powder was all that was needed, and a "Granulated Acacia" has been supplied to the markets ever since, and is now in common use. This is made by coarsely grinding the first picked true Acacia until it all passes through a No. 50 sieve. The finer particles are then all taken out of this coarse powder by careful and thorough use of a No. 80 sieve. This leaves a very uniform, clean, coarse powder, which constitutes the Granulated Acacia. That which passes through the No. 80 sieve is again ground in a finer mill and passed through bolting cloth No. 120, and constitutes the Powdered Acacia, adapted to a different class of The Granulated Acacia is so promptly soluble that it cannot be washed with cold water, as directed by the Pharmacopoeia under the head of Mucilage of Acacia, nor is the washing needed, as the mucilage will be opalescent in either case and not very different. It is, however, true of Acacia, as of other drugs, that the grinding does render the solutions more opalescent, because the particles of bark, etc., which are insoluble are ground up very fine, and because the attrition grinds off fine particles of the mill surfaces. From these circumstances it comes that the finer the powder the more opalescent the solutions made from it.

uses.

The uses of Acacia in medicine are chiefly as a vehicle, a diluent or a demulcent. It is also, doubtless, an aliment of the very sim-. plest and blandest kind. In all these offices or functions it has many duplicates and substitutes, but yet stands at the head of its class, though its advantages are often overlooked through the popular appetite for novelty and change.

As an adjuvant or corrigent for prescription uses, whether in solutions or in powders, it has no superior and perhaps no equal in covering the taste of disagreeable medicines, or in shielding the mucous surfaces against the sudden effects of acid or irritant substances, and its skillful application to its appropriate uses is too much neglected.

ACETA, OR VINEGARS.

This class of preparations gets its distinctive name and character from the use of diluted acetic acid as a solvent for the active principles of the drugs to be exhausted, and to reject the portions of the drugs which are useless or objectionable, and as a solvent the acid has proved to be an efficient one. Dating from the age of Hippocrates, these aceta and their kindred oxymels have come down to the present day with a record of good service in medicine. But their day is past. Better solvents and preservatives, and better and more accurate management of them, and more precise methods of medication, have for many years past gradually tended to supersede the Aceta, so that now they are but relics of the past.

In the presence of the Fluid Extracts they may be said to be quite useless, and they have gradually come to be so little used that the few which remain do not much encumber the overloaded materia medica.

Their decline has been so gradual that in thirty years the number has remained at four in the U. S. Pharmacopoeia, and the present revision still retains these doubtless through a conservative policy, and not from the value of the preparations or from any very considerable use of them. They are, without exception, represented in the Tinctures, and with the exception of opium they are also represented in the Fluid Extracts, and in all they are made without acetic acid. As triplicate preparations which have gradually been superseded, for cause, by a steady progress in medicine, the wisdom of dismissing them would seem no longer doubtful.

They are all now 10 p. c. preparations, and with the exception of opium all are simple, and only the Vinegar of Squill enters into any other preparation. The Vinegars of Lobelia and Sanguinaria are least used of all, and are rarely heard of in modern practice, and never in the records of modern medication. The other two are of more importance and require separate notice.

The Distilled Vinegar, which formerly stood at the head of this class, is now wisely dismissed as an inferior duplicate of the Diluted Acetic Acid, and quite unnecessary in the presence of the latter.

The Acetum or Vinegar of the Primary List of former revisions is dismissed. It was quite useless in medicine, but was an authoritative standard often referred to by Government officers and others for the proper strength and quality of vinegar as a condiment for dietetic uses, and the standard will be missed because it was the only one. Had the definition and tests been improved a little, and

the article been retained, it would have been very useful, and not much out of place in a book of standards, which must embrace some condiments and dietetics. The old standard for strength was that a fluidounce should be neutralized by not less than 35 grains of bicarbonate of potassium. If the fluidounce be taken as 460 grains, this indicates a strength of about 4.56 p. c. of acetic acid, and this is about the strength for ordinary table vinegar, though it might be stronger with advantage.

Macerate the Opium and Nutmeg in fifty (50) parts of Diluted Acetic Acid for twenty-four hours. Put the mixture into a conical glass percolator and return the percolate until it passes clear. Then gradually pour on Diluted Acetic Acid until eighty (80) parts of liquid are obtained. In this dissolve the Sugar by agitation, without heat and strain.

This is a somewhat degenerate successor of what was at first known as the Lancaster Black Drop, then the Quaker's Black Drop, and finally simply Black Drop. It originated in Pennsylvania, and from being largely used there, it was admitted to the Pharmacopœia of 1840 with a good working formula. This formula has stood for forty years, except that Saffron was omitted in 1870, and it is now practically the same as in 1870. In this revision of 1880 the proportion of Opium is reduced from about 16.5 p. c. to 10 p. c., but a fair translation of the definition of the strength of the Opium of the two revisions makes the present powder about one-half stronger than that of 1870, and, therefore, the 10 p. c. of Opium in this preparation now is not very far below the 16.5 p. c. of the Opium of 1870 in therapeutic value, except that it was possible for the Opium of 1870 to be strictly officinal and still be as strong as it now is, and except for the probability that the Opium in use for several years past was really of an average strength much above the pharmacopoeial limits of 1870. From these considerations it is probable that this preparation, though represented as being nearly 40 p. c. weaker in 1880 than in 1870, is really not far from the same