102 ODOEOGEAPHIA. 



is very soluble in alcohol (even when diluted to 50 per cent.), 

 benzene, volatile oils, carbon disulphide, solutions of potash and 

 ammonia, and glacial acetic acid. It is very slightly soluble in 

 petroleum ether. The alcoholic solution is neutral in reaction and 

 gives no precipitate with the acetates of lead nor with lime. It 

 does not yield glucose w^hen treated with dilute sulphuric acid ; 

 strong sulphuric acid dissolves it with production of a brown 

 colour ; hydrochloric acid does not affect it ; nitric acid converts it 

 into a blood-red resinous substance. The sp. gr. of a slightly impure 

 specimen was 1"09 at 15^ C. 



The other constituents of ginger were found by Thresh to be 

 odourless and tasteless resins, starch, mucilage, metarabin, pararabin, 

 organic acids, oxalic acid (as Ca C2 C4), cellulose, albuminoids, 

 vasculose, indifferent substances precipitated by tannin, a substance 

 precipitated by acids, fat (? wax), and from 11 to 14 per cent, of 

 moisture. 



" Black ginger " of commerce is prepared by washing the 

 root in water, boiling for a quarter of an hour, and then drying in 

 the sun. Formerly it was in much greater demand than at 

 present. 



Green ginger is sometimes imported from Jamaica. It 

 consists of soft succulent rhizomes and appears to have undergone 

 but little preparation beyond picking and washing. 



Preserved ginger {Conditum Zingileris) is the delicious 

 preparation received in jars from Jamaica and China, the former 

 being the finest. It is made from the young tubers which are put 

 forth every spring by the perennial rhizome, these are carefully 

 picked, scalded, washed in cold water, and then peeled. The roots 

 are then covered with a weak syrup, and left for two days. The 

 syrup is then poured off and replaced by a stronger syrup, and this 

 is repeated two or three times until the syrup is thick and the 

 ginger bright and nearly transparent. 



The following is given as a superior method of preparing pre- 

 served ginger : — " Pour boiling water on the ginger, and let it steep 

 for a day and night, then peel and pare away all discoloured and 

 hard parts. Boil a syrup of 1 pound of lump sugar to 6 pints of 

 water (this is for 12 pounds of ginger). Put the ginger into a 

 stone jar and pour the thin boiling syrup on it, let this stand for a 



