Chemical and Physical Papers. 97 



and conform in every respect to the above standard. It is clear 

 that in order to obtain these data considerable time and labor 

 are required, and when one has to run through a set of several 

 dozen samples it involves an expenditure of time and labor which 

 is, in some cases, unnecessary, and is certainly uneconomical from 

 the point of view of those who have to bear the expense of the time, 

 the expert help, and the material consumed. 



It becomes, therefore, desirable that a rapid method, as a pre- 

 liminary one for quickly separating the substandard and standard 

 material, be employed. A somewhat indirect method of such a 

 character has been suggested by E. Beckmann, which he calls the 

 cryoscopic method. Mr. Beckmann reviews the difficulties the 

 other processes involve, and these difficulties led him to devise one 

 as above characterized. He based the estimation of spices on the 

 rapid determination of the percentage of volatile-oil constituent. 

 The solvent employed for the extraction of the volatile oil is ethy- 

 lene bromid, on account of its high molecular depression. The 

 examination is performed as follows: Five grams of the powdered 

 drug are macerated in an Erlenmeyer flask for one day with 30 gm. 

 of anhydrous ethylene bromid. As the drug floats on the surface 

 of this liquid it is completely exhausted without much shaking in 

 from eight to ten hours. The solution is filtered through wool, with 

 the aid of the filter-pu mp, directly into the freezing tube or apparatus, 

 and the freezing-point determined in the usual way, the bath being 

 maintained at b° to 6° C. The depression of the freezing-point 

 below that of ethylene bromid observed is due partly to the vola- 

 tile oil and partly to other substances dissolved by the ethylene 

 bromid, and to obtain the former alone a second experiment must 

 be made with a portion (5 gm.) of the drug freed from volatile oil 

 by driving through it a current of steam at 130° C The drug after 

 this treatment is quite dry and can be used at once for the second 

 extraction. The difference between the depression observed for 

 the crude spice and for the spice deprived of volatile oil gives the 

 depression due to the volatile oil. For estimating the quality of a 

 spice by comparison with one of known standard strength, it is only 

 necessary to make a determination using the standard as one, and 

 another using the sample example to be estimated. 



' While Beckmann's method is comparatively short and rapid, it 

 is less elaborate than process of extraction with petroleum spirit 

 or ether and estimation of volatile ether extract. It has some of 

 the disadvantages of the volatile ether extract method, in that it 

 bases the estimation mainly on the volatile oil. In many cases the 

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