378 Maugham.—Observations on the Osazone Method 
regard to cane sugar which were founded on evidence other than that derived 
in the above manner can be regarded as at all trustworthy. 1 
The identification of maltose by the formation of osazones does not 
appear to have been investigated by Senft. 2 
Grafe 3 noted and figured the characteristic flat, broad needles of 
maltose phenylosazone as yielded by Senft’s reagent, and such crystals 
have also been figured by the present writer in an earlier paper. 4 
In the experiments just described, and in others of a similar character, 
the process of formation of the crystals of maltose phenylosazone was 
followed under the microscope. 
It is slow and changes may take place over many days, though with 
the stronger solutions, or with more prolonged heating, the time is 
shortened. 
The liquid first changes to a deeper yellow, and small drops looking 
much like ‘ golden syrup* appear, the amount of this syrup being roughly 
proportional to the concentration of maltose present. These drops gradually 
become confluent to form larger drops, or by partial union they may form 
irregular chains of globules, or again they may yield masses whose contours 
show obvious signs of their formation by the coalescence of smaller globules. 
These larger drops of yellowish-brown to very pale yellow syrup may 
undergo no further change, or if the concentration is sufficiently high they 
may begin to show signs of the formation of radially arranged, needle- 
shaped crystals. Ultimately the larger drops give rise to fairly regular, 
spherical clusters of rather broad, straight, light yellow needles whose points 
are usually more or less obtuse. Besides these regular, spherical clusters of 
radiating crystals other more irregular arrangements are to be found as well 
as single needles. Frequently a number of crystal clusters form in contact, 
and become arranged in straight or irregularly curved rows with slight con¬ 
strictions indicating the component clusters. Often the osazone appears as 
an almost opaque mass, the crystalline nature of which cannot be made out, 
or is perhaps only recognizable at portions of the external surface. 
Examples of these forms are shown in PL XVII, Figs. 4-7. 
The formation of crystals of maltose phenylosazone after heating for 
one hour depends then in part upon the original concentration of the sugar 
in the glycerine, and it seems to be hindered by the great viscosity of this 
liquid. In low concentrations the syrup stage of the osazone may not be 
1 Cf. also below, p. 379. 
3 Senft records ( 1 . c., p. 25) that in a few instances, after the preparations had stood for some 
fourteen days, rosettes and sheaves of yellow crystals formed. He considered that these were 
probably osazones. Cf. PI. II, Figs. 8-11, where characteristic crystals of maltose phenylosazone 
are shown in Ginkgo , Daucus , and Elodea. 
3 Grafe, 1 . c., PI. I, Figs. 4 and 5. In the latter crystals are apparently forming from yellow 
liquid. 
4 Mangham (’ll), p. 164, Figs. 3 and 4. See also Plimmer (’ 10 ), p. 71, Fig. 14. 
