20 COMMERCIAL SICILIAN SUMAC. 



INVESTIGATION OF 1907. 



During 1905 and 1906 there was so much agitation of the question 

 of sumac adulteration in the leather trade journals, and buyers had 

 to become so well informed on the question, that it was thought 

 advisable again to collect and examine samples. This was done in 

 the spring of 1907, exactly as before, the samples being secured from 

 all incoming consignments for a time before they passed into the 

 hands of the consignee. The results of the examination of these 

 samples are given in Table III, page 22. 



DISCUSSION OF ANALYTICAL DATA. 



Seventy-five per cent of the 53 samples examined were pure sumac 

 or contained but traces of other material such as may have been 

 present accidentally. The pure samples contained from 25.6 to 

 35.7 per cent and averaged 30.6 per cent of tannin, or 1.3 per cent 

 lower than the 1905 samples. Microscopical examination showed 

 that 25 per cent of the samples examined were adulterated with 

 lentiscus, while one sample was pure lentiscus and another was Turkish 

 sumac. The adulterated samples contained from 22.4 to 30.4 per 

 cent and averaged 26.3 per cent of tannin or 0.3 per cent lower than 

 the 1905 samples. These facts indicate that while adulteration is 

 not so generally practiced as in 1905, individual shipments are 

 apparently adulterated to about the same extent. 



The lowest tannin content of all the samples was 22.4 per cent, the 

 highest 35.7 per cent, and the average 29.4 per cent, the latter figure 

 being practically identical with the average tannin content of the 

 1905 samples. Color tests were made on but few extracts, which 

 indicated a somewhat higher average color in the pure 1907 samples 

 than in the pure 1905 samples. Only 3 of the 13 samples which 

 were found to be adulterated were labeled to that effect. The other 

 samples were either labeled pure sumac or marked so as to give the 

 impression that they were pure Sicilian sumac. 



These results indicate that from 1905 to 1907 there was a decrease 

 of about 16 per cent in the importation of adulterated shipments of 

 sumac, but that those shipments which were sophisticated had been 

 adulterated with practically the same percentage of lentiscus as 

 formerly. The practice of labeling adulterated shipments "pure 

 sumac" or " warranted 100 per cent pure sumac" appears to be as 

 general as formerly, so that it is still absolutely necessary for a buyer 

 who would be sure that he is purchasing a pure, high-grade sumac to 

 have it examined. 



117 



