Chap. 5.] Gum Arabic, We. 43 



the bark of particular trees. ' Ic is obfervable, that fao 

 chcirine fruits, when four and unripe, are found to con- 

 tain gum and an acid; whence it {eems not unfair to 

 conclude, that faccharine matter is formed of thefe ma- 

 teri. Is, operated on by the procefs of vegetation. 



The moft common gums are i. Gum Arabic, 

 which flows from the acacia in Egypt and Arabia, and 

 is of the fame nature with gum Senegal, which is fome- 

 limes fold inftead of it. 2. Gum tragacanth, which is 

 obtained from a thorny bufo, growing in Crete, Afia, 

 and Greece. 3. The gum which flows from certain 

 trees growing in this country, particularly apricot and 

 plum-trees. The efTential characters of all thefe gums 

 are the fame, but gum tragacanth is by far the moft 

 powerful in producing a thick and tenacious mucilage. 



II. SUGAR. The mixed and various properties of 

 this fubltance, have rendered chemifts very doubtful 

 to what clafs of bodies it ought to be referred. By 

 fome it has been called inflammable, by others faline, 

 and by others it has been clafied among gummy and 

 mucilaginous matters. Sugar is foluble, both in water 

 and ardent fpirit. It is more inflammable than gums, 

 and has not been proved to contain any fait ready 

 formed, except fome fixed alkali. It is the only prin- 

 ciple the prefence of which enables fluids to take on the 

 vinous fermentation. 



Saccharine matter is found in a great number of ve- 

 getables j fuch as the maple, the birch, the red beet, 

 the parfnip, the grape, farinaceous grain, potatoes : 

 Margraff indeed extracted it from moft vegetables ; 

 and it is well known that honey is a faccharine matter, 

 collected by the inftincl: of' the bee from an infinite 

 variety of plants, but principally from flowers. The 

 pundo faccharifera or fugar-cane contains this matter 



however 



