55 



There arc other substances which are sometimes used as con- 

 dimentals, but which camiot be taken up at this time. Some 

 of them are placed in other parts of this bulletin, where it is thought 

 they more properly belong. 



A few, which have been reported rarely, have been left out, 

 as it is believed that they are of little importance. 



PART V. 



IDENTIFICATION OF CHEMICALS AND MISCELLANEOUS 



SUBSTANCES. 



ALUM. 



Alum is sometimes added to the so-called condimental stock- 

 foods and if present is usually in sufificient quantity to be easily 

 detected by its characteristic taste. This cannot be easily des- 

 cribed, but is more or less acid and bitter, and when touched to 

 the tongue "puckers" the skin at that point. If alum is suspected 

 but cannot be positively identified by the taste, the following 

 test may be used. A portion of the sample, or particles thought 

 to be alum, may be shaken up with 10 c.c. of water in a test tube, 

 and 1 c.c. of an alcoholic tincture of log^vood added (5 gm. log- 

 wood digested in 100 c.c. alcohol), then 1 c.c. of a saturated so- 

 lution of ammonium carbonate added, and the whole shaken 

 for some time. If alum is present the mixture will have a decided 

 lavender blue color, w^hich will remairi for some time. This meth- 

 od is applicable to cattle foods and gives a good indication as to 

 its presence or absence in condimentals. The presence of alum, 

 is, however, not a usual thing in foods. 



ARSENIC. 



This substance has been reported in certain foods, but has 

 never been found by the author. Its presence or absence may be 

 detected by the well known "Marsh Test", a description of which 

 may be found in any good anal^-tical work. The chemical analysis 

 will usually reveal its presence. It is of very rare occurrence in 

 condimentals. 



