SPICES AND CONDIMENTS. 165 



cells, neither of which are 'seen prominently in the substances which 

 are adulterated. 



These suggestions of the peculiarites of the different adulterants 

 should, of course, be confirmed and supplemented, and the eye accus- 

 tomed to recognize their structure by means of a study of the actual 

 substances, which should always be at hand in the dry and ground con- 

 dition for reference. Quickness and certainty will be much advanced 

 by such facilities. 



Reference may also be fittingly made here to chemical operations of 

 a general nature, which are applicable to all the spices. 



CHEMICAL EXAMINATION. 



Determinations of a quantitative nature should include 



Water. A portion of the powdered spice which should pass a 60- 

 mesh sieve, one gram, is to be dried at 105 to 110 C. in an air 

 bath, provided with a regulator, until on successive weighings a gain is 

 found showing that oxidation has begun. Twelve hours, or overnight, 

 usually suffices. The loss is water, together with the largest part of 

 the volatile oil. Deduction of the volatile oil, as determined in the 

 ether extract, will give a close approximation to the water. 



Ash. In the same portion the ash is determined by incineration at a 

 very low temperature, such as may be best obtained in a gas muffle, 

 which is a most convenient arrangeuient for work of this description, 

 and far superior to any kind of lamp or burner. The proportion of ash 

 insoluble in acid may also be determined where there is reason to be- 

 lieve that sand is present. 



Volatile oil and ether extract. Two grams of the substance are ex- 

 tracted for twenty hours in a siphoning extraction apparatus on the 

 Soxhlet principle, with Squibbs's best ether. The apparatus we use in 

 this laboratory, arranged by Mr. A. E. Knorr, he describes as follows: 



The substance under examination is placed in a test tube, which is then 

 inserted into a continuous extraction apparatus of the intermittent si- 

 phon class. The tubes used for this purpose are ordinary test tubes, 

 the bottom of which has been blown out. A wad of washed cotton of 

 sufficient thickness is put into the lower end of the tubes to prevent 

 any solid particles of the sample from finding their way into the receiv- 

 ing flask ; another wad of cotton is packed on top of the sample, and 

 the apparatus is then so adjusted that the condensed ether drops into 

 the tube, and, percolating through the sample, siphons into the receiving 

 flask, when the operation is continued ad infinitum. 



It is absolutely necessary to use the best Squibbs's ether in order to 

 avoid extracting substances other than oil and soluble in alcohol, and to 

 continue the extraction for at least the time named, as piperine and 

 several other proximate principles are not extremely soluble in ether. 

 If these precautions are followed we have found no difficulty in extract- 

 ing all the piperine, for example, and obtaining duplicate results of 



