May, 1882.

for identification from a provincial town. It appears desirable, therefore, as the false belladonna roots are to all appearance likely to be distributed through the country, to publish a figure of the false root and to give an account of the means by which it may easily be distinguished from the true belladonna root.

The root here alluded to has been identified by Professor Flückiger as that of Medicago sativa, and is stated by him to be sometimes met with on the continent as an adulterant of belladonna root.

In size and color the medicago root closely resembles that of belladonna, but differs in the following particulars:

The crown of the root is divided into 3 or 4 woody branches which are solid. The tap-root is hard and woody and broken only with difficulty. The outer surface is more or less covered with small scattered warts, and when scratched with the nail does not leave a white mark. The transverse section presents a woody structure and when it is wetted the cortical portion is seen to be of a white color with a yellowish meditullium traversed by a number of white medullary rays (Fig. a). When the transverse surface of the root is moistened a leguminous odor, somewhat resembling that of the pea, becomes perceptible, and the flavor is similar. The taste of the root is at first sweet like that of liquorice and afterwards bitter and somewhat acrid, irritating the fauces.

Belladonna root is generally crowned with the hollow bases of the leafy stems, and the epidermis is easily scratched off by the nail, leaving a white starchy spot wherever abraded. The transverse surface of the root exhibits a narrow cortical portion of a yellowish or pale brown color, divided by a dark line from the large meditullium or central portion. The latter is also of a pale brown color, and shows, irregularly

Root of Medicago sativa.-a, transverse section of root. b, transverse section of belladonna root.

scattered through its substance, but more numerous towards the cor

tical portion, a number of darker dots (Fig. b), which when examined through a lens are seen to be vascular bundles in which the openings of the large porous vessels are visible, the vessels being surrounded by a few wood cells which give the dark color to the dots. The taste of the root is starchy and slightly bitter, without subsequent acridity. The root breaks with ease. Both the medicago and the belladonna contain starch, the grains being much larger and more muller-shaped in belladonna, and forming sometimes duplex or triple granules; other granules appear circular or oblong oval, according to their position. In medicago the starch grains are somewhat similar, but smaller. There are also present in the latter root a number of linear-oval grains, presenting a well marked linear hilum. There is much less starch in the root than in belladonna, and the iodine test therefore gives a comparatively faint reaction. Neither root appears to contain tannin. The best marks by which to distinguish the medicago root therefore are the radiated structure of the meditullium, its woody character, and consequent resistance when an attempt is made to fracture it.

It may be added that the root was of German origin, and that those who wish for genuine root would do wisely to order the English grown drug, which is collected and prepared with more care.— Farm. Jour. and Trans., March 11, 1882.

A NEW DISPLACEMENT APPARATUS.

BY R. F. FAIRTHORNE, PH.G.

A somewhat novel and in some respects apparently very useful percolator has been brought to my notice, together with the manner in which it is employed, and some articles produced by using the same, that possess properties showing that they were well made; in fact, some of the fluid extracts were not only fair, but unusually good, and for this reason I thought that a description of the percolator and of the manner in which it is used might be as acceptable to others as it was to me. By referring to the annexed cut the use of each part will easily be understood. The shape of the percolator differs somewhat from the usual form, being to some extent egg-shaped, and articles packed in it are not so liable to become so compressed as to impede percolation, as is sometimes the case when the ordinary form of displacer is used which more nearly approaches the cylindrical form. The cover B, which is hemispherical in shape, is fastened unto the body A

of the displacement apparatus, by means of clamps with India rubber rings between to render it air tight. The drug to be operated on having been previously sufficiently moistened with the menstruum and packed is next exhausted of as much air as possible by a vacuum being produced through the upper part of the vessel, by means of an air

pump G, which is connected with it by means of the tube F. The stop-cock h is next closed and M opened, connecting with the tube E, the end of which dips into the liquid to be employed as menstruum, and thereby a sufficient quantity of it is allowed to be drawn into the

displacer to cover the drug. The stop-cock M is then closed and the materials allowed to macerate for several days.

In order to start percolation, the receiver C is exhausted of air and the tap i having been opened the saturated fluid will begin dropping, and continue to do so, so long as the force of the vacuum in the receiver is equal or greater to that in the upper vessel. When it begins to stop, air is admitted above the drug which is drawn through the material, carrying with it much of the remaining liquid. To finish the operation air is forced into the percolator by means of the pump. Messrs. Smith, Kline & Co., of this city, who have adopted this apparatus for making fluid extracts, state that they find it works very satisfactorily and economically as so large a proportion of the menstruum used is recovered. As an instance in making fluid extract of Wild Cherry, when 80 pounds of the bark are used 80 pints only of liquid are employed and at least 75 pints are recovered.

From what is here stated it will be apparent that the superiority of this mode of extraction of those active ingredients, that the fluid extracts and tinctures should contain, depends chiefly upon two conditions to which the drug operated upon is subjected, namely, upon the effect produced by withdrawing the ordinary pressure of the atmosphere, not only on the surface of the material, but on each particle of the substance; a vacuum being thereby produced in each individual cell which is at once filled up upon contact with the liquid when it is admitted into the vessel, the menstruum under these conditions being enabled to penetrate much more quickly and readily the interior of each granule of the article operated upon.

The advantage of the other condition consists of exclusion of air, by means of the cover and retention of vapor of the fluids used in making the preparations, preventing thereby changes which might otherwise occur, both in the liquid and solid contents of the percolator.

As only such drugs are used that have been well dried, we can understand readily the difficulty with which many of them are exhausted by the usual process, when we take into consideration that each particle of the drug is composed of cells which, by desiccation, become partially empty, offering a certain amount of resistance to the entrance of liquids in somewhat the same manner that a piece of pumice-stone or pith of sassafras resist the penetration of water when thrown into it. Therefore, if a vacuum can be formed in these cells, fluids will much more readily surround and penetrate them.

In using this apparatus for preparing fluid extracts only one pint of menstruum for every sixteen ounces of the material is employed, and after the liquid has ceased to run into the receiver, more menstruum is added, just sufficient to produce a pint of the finished product. No evaporation of any portion of the tincture is required as in the officinal

process.

By means of suitable iron pipes any number of percolators and receivers may be connected with a stationary air-pump, and after closing the stop-cocks of the others the air in any one vessel may be rarefied or compressed at pleasure.

SYRUP OF HYDRIODIC ACID.

BY W. GILMOUR.

An American preparation of hydriodic acid in the form of a syrup has lately been brought under the notice of medical men and pharmacists in this country, with the recommendation that the acid "is perfectly protected against decomposition-a result never before attained." Into the composition of this particular syrup, or its preservative medium, I will not at present enter, but I wish to point out that the statement here made, as also that in the recommendatory advertisement, that "simple mixtures of hydriodic acid and syrup do not keep," are only partially correct.

Nearly thirty years ago, when this preparation was first introduced, Mr. Murdoch, of Glasgow, showed that a syrup of this acid could be kept with ordinary care for an indefinite period. This is my own experience also. With attention to the conditions afterwards to be referred to, there is less trouble from decomposition with a syrup of this acid than there is with a syrup of any of the ordinary ferrous preparations.

It will probably be remembered by many that Dr. Buchanan, who was the first to bring this acid prominently under medical notice as a therapeutic agent, recommended that it should be prepared extemporaneously by double decomposition of concentrated solutions of iodide of potassium and tartaric acid. When prepared in this way the resulting liquid is of a bright yellow color, deepening quickly into a darker red, and giving abundant indications of the presence of free iodine within a very short time of its preparation. Mr. Murdoch attributed