2G 
MR. F. SUTTON ON VARIETIES OF SUGAR. 
and Banana of the West Indies, Beside these there is the Sugar- 
date (Phoenix si/lvestrisj, known as the wild Date of Bengal. 
Darwin in his ‘Journal of Besearches,’ speaks of a Palm (Juhcea 
gpectabilis) which abounds in central Chili, and yields a very 
sweet sap, which the natives make into a syrup, and call it 31 id de 
jydma, or Pahn-hone 3 u With his characteristic power of obser- 
vation, he notices that when these trees are cut down in the early 
spring, and the crown of leaves is lopped off, the sap begins to 
flow from the upper end, and continues for several months ; it is 
necessary, however, that a thin slice ho shaved off that end every 
morning, so as to expose a fresh surface. A good-sized tree will 
yield as much as ninety gallons, and the whole of this liquid 
must have been contained in the vessels of the apparently dry 
trunk. The sap flows much more freely on those days when the 
.sun is powerful ; and moreover it is necessary to cut the tree down 
so that its upper end slopes upward on the side of the hill where 
it grows. If it lies the other way, scarcely any sap will flow, 
although in that case one would think that the action would be 
aided, rather than checked by the force of gravity. This movement 
of the fluid is no doubt due to osmotic force. 
Bow all the Sugars arising from the sources named, and 
hosts of similar sources, are precisely alike in constitution, 
and the Sugar is distinguished by chemists as Cane-Sugar, 
Saccharose, or Sucrose. 
2. We now come to the second chief variety of Sugar, namelj', 
that which constitutes the sweetness of ripe fruits, such as Grapes, 
Figs, Currants, and so on, also the sweet prineiple of honey. This 
kind of Sugar is known as Grape-Sugar, or Glucose. There is a 
true chemical difference between these two principal varieties of 
Sugar, and they can be readily distinguished from each other'by 
specific chemical and optical tests. The remaining varieties are 
very numerous, but they are all distinguishable from the two chief 
kinds, and from each other. Among this class may be mentioned 
INIaltose from malted grain. Sugar of Milk, Mannito, which is con- 
tained in tlie ordinary manna of the chemist’s shop, Glycyrrhizine 
or Sugar of Licorice, and so on. 
It must bo remembered that the Sugars I have described are 
all of natural production ; but there is at the present time, an 
enormous amount of energy developed in the artificial manufacture 
