=Raffinose= occurs normally in cotton seeds, in barley grains, and in manna; also, in small quantities in the beet root, associated with sucrose. It is more soluble in water than is sucrose and hence remains in solution in the molasses from beet-sugar manufacture, which constitutes the commercial source for this sugar. Raffinose crystallizes out of concentrated solutions, with five molecules of water of crystallization, in clusters of glistening prisms. It is strongly dextrorotatory, the anhydrous sugar having a specific rotatory power of +185°, and the crystalline form, C_{18}H_{32}O_{16}, showing a specific rotation of +104.5°. It does not reduce Fehling's solution, nor form an osazone, and in its other properties it closely resembles sucrose. The hydrolysis of raffinose presents several interesting possibilities. If its structure is represented as follows: C_{6}H_{11}O_{5}-C_{6}H_{10}O_{4}-C_{6}H_{11}O_{5} Fructose Glucose Galactose \______ _____/ \_______ ______/ \/ \/ Sucrose Melibiose it is apparent that it may break down by hydrolysis in three different ways: (1) into sucrose and galactose, (2) into fructose and melibiose, and (3) into fructose, glucose, and galactose. As a matter of fact, it does actually break down in these three different ways, under the influence of different catalysts; invertase or dilute acids break it down into fructose and melibiose, emulsin hydrolyzes it to sucrose and galactose, while strong acids or the enzymes of bottom-yeasts break it down into the three hexoses. =Gentianose=, a trisaccharide found in the roots of yellow gentian (_Gentiana lutea_), is a non-reducing sugar, which when hydrolyzed yields either fructose and gentiobiose, or fructose and two molecules of glucose. =Melizitose=, a trisaccharide which, in crystallized form, has the formula, C_{18}H_{32}O_{16}·2H_{2}O, occurs in the sap of _Larix europea_ and in Persian manna, and has recently been found in considerable quantities in the manna which collects on the twigs of Douglas fir and other conifers. When hydrolyzed, it yields one molecule of fructose and one of turanose, a disaccharide containing fructose and glucose linked together in a slightly different way than they are in sucrose. Turanose itself is a reducing sugar, but when linked with fructose to form melizitose its reducing properties are destroyed. Melizitose is a very sweet sugar. TETRASACCHARIDES