SPICES. 55 



IX. TEA AND COFFEE, 



By W. H. ELLIS, 

 District Analyst, Toronto, Canada. 



It has been found impossible to prepare the report on this subject this year. The 

 heading is inserted here to preserve its proper order. 



X. SPICES. 



By A. L. WINTON, 

 Oiemist of State Experiment Station, New Haven, Conn. 



1. GENERAL DISCUSSION. 



The microscope is a most valuable means of detecting adulterants of vegetable 

 origin in spices, as it usually discloses the particular adulterant present, even when 

 in small amount. 



Quantitative determinations are made, either to corroborate the results of the micro- 

 scopical examination, or to detect exhausted spices, mineral matter, and other adul- 

 terants which do not have distinctive microscopic characters. a 



2. PREPARATION OK SAMPLES. 



Grind the sample so as to pass a sieve with round holes one millimeter in 

 diameter. For the determination of starch in pepper by the diastase method, reduce 

 a portion of the sample to an impalpable powder, by grinding in a mortar. 



3. DETERMINATION OK WATER." 



Dry two grams at 110 C. to constant weight. From the loss in weight thus sustained 

 subtract the amount of volatile ether extract determined as below described. This 

 method, described by Richardson, 1 ' gives a close approximation to the true percent- 

 age of moisture. 



4. DETERMINATION OF TOTAL ASH. 



Follow the method of the Association. If calcium carbonate is present, care must 

 be taken to burn the material and also the residue after exhaustion with water, at a 

 heat below redness, thus avoiding loss of carbonic acid of the carbonate. When 

 leaching with water is necessary, it is advisable to add a few drops of ammonium 

 carbonate solution before evaporation. 



5. DKTKKM i NATION OF ASH SOLUBLE IN WATER. 



Boil the ash prepared as above with 50 cc of water, collect the insoluble portion 

 in a Gooch crucible, wash with hot water, dry, ignite, and weigh. d Subtract the 

 percentage of insoluble ash thus determined from the percentage of total ash, thus 

 obtaining the percentage of water-soluble ash. 



6. DETERMINATION OF "SAND" OR ASH INSOLUBLE IN HYDROCHLORIC ACID. 



Incinerate 2 grams of the material as above directed, boil with 25 cc of 10 per 

 cent hydrochloric acid (sp.gr. 1.050) for 5 minutes, collect the insoluble matter in a 

 Gooch crucible, wash -with hot water, ignite, and weigh. 



See also Appendix, p. !.>_'. 



*U.S.Dept.Agr..l>iv.rhrm..Bul. lit. I'art 2, p. ir..\ 

 "U.S. Dept.of Agr.,I>iv.nf Chcni., Bui. If. revised, p. 23. 

 d Conn. Agr. Kxpt.Sia. IN-pi. iv.is, p. IN;. 



