APPENDIX. 679 
A temperature of about 35° C. is the most favorable for this fermen- 
tation. Dextrose readily reduces copper salts in the presence of caustic 
alkali. 
Maltose. C.2H220u. 
This sugar may be artificially produced by the action of diastase, a 
ferment obtained from malted barley, on starch. 
38CeHi00s + H2O = CiaHe2O1 + CoHi00s. 
Starch. Maltose. Dextrin. 
It may also be formed by the action of dilute sulphuric acid on 
starch. It reduces copper salts; is dextro-rotatory; ferments with yeast, 
and erystallizes in fine needles. It seems to be the principal sugar 
formed in the natural digestive processes. 
Milk-Sugar (lactose). Ci2Ha2On. 
This form of sugar is found in the milk of all animals normally, and 
occasionally in the urine of animals during lactation. 
It crystallizes in rhombic prisms ; its taste is slightly sweetish; is 
dextro-rotatory ; much less soluble in water than cane-sugar. When 
the lactose of milk ferments; it breaks up into alcohol and lactic acid, 
hence the souring of milk. It reduces solutions of copper salts, but less 
perfectly than dextrose, and is dextro-rotatory. 
Inosit. CeHi20c. > 
This substance has been obtained sparingly from the muscle-cells of 
the heart and from some other organs. It crystallizes in rhombic 
prisms; readily soluble in water but insoluble in alcohol and ether. This 
sugar has no specific action on light, and is susceptible ot the lactic fev- 
mentation. 
Dextrin. CeHwOs. 
This substance may be formed by the action of dilute acids on starch, 
or by the action of diastase on the same body. It is strongly dextro- 
rotatory, does not reduce solutions of copper salts, gives a red color 
with iodine, is soluble in water, and precipitated by alcohol. It is a 
product of both artificial and natural digestion. 
By the action of acids and ferments on starch, certain modifications 
of dextrin are formed. Of these, erythrodextrin becomes sugar by the 
continued action of ferments. Achroodextrin remains unaltered and is 
characterized by giving no red color with iodine. It may be converted 
into dextrose by boiling with dilute hydrochloric acid. 
Glycogen. CsH10Os. 
This substance is pretty widely distributed in the organs of the body 
especially in the mammalian fcetus, and is found in abundance in the 
liver of the adult in both vertebrates and invertebrates. Glycogen when 
pure is white, amorphous, tasteless, easily soluble in water, insoluble in 
alcohol and ether, highly dextro-rotatory, and does not reduce metallic 
oxides. It is changed by the digestive ferments into a form of sugar 
and of dextrin, and gives a red (port-wine) color with iodine, which dis- 
appears on warming but returns on cooling, by which latter it is distin- 
