United States Pharmacopoeia method for belladonna in the details of extracting the drug, but instead of shaking out the ethereal extract with acid, the former is to be evaporated, ammonia expelled by repeated addition of a few cubic centimeters of ether and evaporation, and the impure residue titrated. It might either be dissolved in alcohol diluted with water and titrated with acid, or dissolved in excess of standard acid and the excess of acid titrated with standard alkali, preferably with iodeosin indicator. This method, he thinks, could be adapted for many alkaloidal drugs. Professor Ruddiman criticises the use of decinormal acid, especially in titrating an alkaloid of such high molecular weight as aconitin, where a slight difference in measurement seriously affects the result.

In Method II as well as in I, Mr. Lyons obtained a further yield of about 0.1 per cent of alkaloid by shaking out with chloroform following the final extraction of the alkaline liquid with ether. Mr. Pearson redissolved the alkaloidal residues from the gravimetric determinations in (II) in acid and purified by submitting them to a shaking-out process with ether, obtaining much lower results, viz, 0.312 and 0.315 per cent. In view of the fact that both methods gave practically the same average volumetric result and variability, the greater convenience and rapidity of Method II are in its favor.

BELLADONNA LEAVES.

This sample was delivered as No. 60 powder. The following proportions passed through the respective sieves:

A considerable amount of coarser powder than the Pharmacopoeia permits in assay samples of belladonna leaves was present. By Method I (U.S.P.) the few gravimetric results reported varied exceedingly, none of them coming within 10 per cent of the average, and only 14 per cent within 15 per cent of the average. Of the volumetric results, 41 per cent came within 10 per cent and 65 per cent within 15 per cent of the average. By (II) gravimetric, 86 per cent of the few results were within 10 per cent; also 86 per cent within 15 per cent of the average. Of the volumetric results by (II) 39 per cent came within 10 per cent, and 73 per cent within 15 per cent of the average. The average results by (I) are slightly higher than by (II), but both are somewhat under the United States Pharmacopoeia standard of 0.30 per cent. A slight impurity in the residues is indicated by the higher gravimetric results. In (I) Mr. Hankey used 2 cc of ether to assist solution of the alkaloidal residue in acid, expelling it by gentle warming before titration. J. G. Francis and Parker used 50 cc more ether-chloroform mixture than directed to exhaust the drug. It has been observed in the Drug Division when assaying belladonna leaves and root and coca leaves by the pharmacopoeial method that a large portion of the last 50 cc of solvent mixture which is intended to complete the percolation has to be used in rinsing the drug into the percolator. The drug should be packed after it is all transferred and percolation carried to practical exhaustion. The combined acid solutions obtained by shaking with the percolate should be shaken with fresh solvent in small portions until no more color is removed before making alkaline and shaking out the alkaloid. Instead of measuring out 3 cc of decinormal sulphuric acid to dissolve the alkaloid, a number of workers in such

a Workers in the Division of Drugs recommend cylindrical nursing bottles (8 ounces) which taper to the neck without any shoulder instead of Erlenmeyer flasks for digesting the drug with solvent, as the former are more easily clamped on a mechanical shaker.

cases prefer to add an equivalent amount of fiftieth-normal acid as a quantity less liable to error in measurement.

In (II) Mr. Blome suggests increasing the amount of ether-chloroform mixture for extracting the drug to 180 cc and decanting 120 cc. Mr. Fuller suggests that instead of directing the use of neutral alcohol for dissolving the alkaloid before titration it would be preferable to compare the result with that of a blank titration made with the same amount of the same stock of alcohol, water, and indicator. Mr. Hankey reports dissatisfaction with the titration results owing to an indefinite end reaction. Though his alcohol was redistilled over alkali, a blank titration with the amounts of acid, alcohol, and water directed required only 14.3 cc of fiftieth-normal alkali, while the same amount of acid by direct titration required 15 cc of the standard alkali. Mr. Parker prepared "neutral" alcohol by adding fiftieth-normal potassium hydroxid to alcohol until a blank titration with the amounts of acid, alcohol, and water directed agreed with a direct titration of the acid alone. This method or that suggested by Mr. Fuller eliminates the effect of any deviation from neutrality by the alcohol or water under the working conditions. Mr. Lyons made a parallel experiment, evaporating the ether-chloroform extract of the drug instead of shaking out with acid and titrating the residue directly, as outlined in the discussion under aconite root. The result was 0.32 per cent.

BELLADONNA ROOT.

This sample was delivered as No. 60 powder, and passed through the several sieves in the following proportions:

No. 80.
No. 60.

Total.......

Grams.

98

99

It was, therefore, somewhat finer than the Pharmacopoeia requires for assay samples of this drug. By Method I (U.S. P.) of the few gravimetric results 29 per cent came within 10 per cent of the average and 43 per cent within 15 per cent. Of the volumetric results, 46 per cent came within 10 per cent of the average and 80 per cent within 15 per cent. By (II) the gravimetric results varied more than the similar determinations by (I). The volumetric results by (II) were decidedly better than the corresponding results by (I), 73 per cent coming within 10 per cent of the average and 85 per cent within 15 per cent. The averages by the two volumetric determinations are practically identical, likewise those by the two gravimetric determinations, but no explanation is apparent for the fact that by both methods the gravimetric results average lower than the volumetric. This relation occurs also in four instances (in II) where the results apparently represent the same residue.

In (I) Mr. Hankey dissolved the alkaloidal residue in 1 cc of neutral alcohol before adding excess of standard acid and titrating back with half-strength limewater, comparing the same with a blank titration. C. H. La Wall made parallel assays by both methods, evaporating the ether-chloroform extract instead of shaking out with acid, and titrating the impure residue directly, the results obtained being (I) 0.514 and (II) 0.529 per cent, duplicate results agreeing well. J. G. Francis used 25 cc, and Mr. Parker 50 cc more ether-chloroform mixture than the amount directed to extract the drug. Their results are all well above the average. The remarks made in the discussion on belladonna leaves, Method I, regarding the percolation of the drug also apply to belladonna root. With belladonna root Method II, by evaporation of the ether-chloroform extract, and direct titration of the impure residue, Mr. Lyons obtained a value of 0.617 per cent.

COCA LEAVES.

This sample, delivered as No. 60 powder, passed through the several sieves in the following proportions:

A large portion of the powder was coarser than the pharmacopœial requirement for assay samples of this drug. The gravimetric results by Method I (U. S. P.) are too few to justify any conclusions. Of the volumetric results, 36 per cent come within 10 per cent and 58 per cent within 15 per cent of the average. Of the gravimetric results by (II), 75 per cent come within 10 per cent and 82 per cent within 15 per cent of the average. Of the volumetric results, 33 per cent come within 10 per cent and 72 per cent within 15 per cent of the average. The gravimetric averages and likewise the volumetric averages by the respective methods are in substantial agreement, the gravimetric results being somewhat higher than the volumetric, owing probably to impurities in the alkaloidal residue. In (I) Mr. Fuller accomplished the final shaking out with three portions of 20 cc each of ether instead of 25, 20, and 15 cc. He thinks the drug should be digested with the solvent mixture longer than one hour, as the marc in this case still contained alkaloid. Mr. Hankey dissolved the alkaloidal residue with 1 cc of "neutral spirits" and titrated with acid and diluted limewater as with belladonna root. Cochineal gave an unsatisfactory end reaction. Messrs. La Wall and Parker noted considerable emulsification in shaking out by both methods. The latter used 50 cc more solvent than is directed for percolating the drug, and J. G. Francis used 75 cc more, and shook the drug finally with five portions of 25 cc of ether. The extraction was not complete.

For coca as for belladonna the amount of solvent mixture directed in the United States Pharmacopoeia method is scarcely adequate for the proper manipulation and extraction of the drug. In the final shaking out process further extraction with ether is desirable. In (II) Mr. Blome suggests increasing the ether-chloroform mixture to 180 cc and decanting 120 cc. Mr. Hankey obtained a better end reaction with iodeosin than with cochineal. Professor La Wall obtained equally low results in a duplicate assay. J. G. Francis found that the final extraction was not complete. Mr. Pearson could not decant 100 cc without forcible expression, and therefore objects to the method. As in (I), further extraction with ether in the final shaking out is probably desirable.

In both (I) and (II) considerable impurity evidently passes into the alkaloidal residue, and a more thorough washing with solvent before making alkaline is indicated.

THE MACROSCOPY AND MICROSCOPY OF DRUGS.
By H. H. RUSBY.

The object of this brief paper is to direct the attention of the members to the importance of chemists supplementing their chemical methods by suitable physical methods in identifying and estimating drugs; and to the facility with which the chemist can acquire enough knowledge of such physical methods, and of the physical properties of drugs, to be of great assistance in his analytical work.

When the subject of the chemical standardization of vegetable drugs was being agitated in connection with the approaching United States Pharmacopoeia Convention of 1890, the writer was astonished to hear Prof. John M. Maisch declare himself