COLLOIDAL XOLUTIONX

207

curve show a nuddon drop in fluidity at about 30 per cent?77 The
glyeogen suspensions were studied by Botazzi and iPErrieo (1906)
using two different viKcorneters, one from 0 to 20 per cent and
the Heecmd from 20 per cent on. On plotting the fluidities wo
find that the values for eaeh viscometor lie on a straight lino, but
the two linos do not coincide. For the first vinoornotor, the fluid-
ity of wafer is 144.0 and the weight concentration of zoro fluidity
in 27.5, while for the second viscomoter it is necessary to assume
a iluidity for water of 77.0 and a zoro fluidity at 4.1 per cent
concentration. Using formula (64) the calculated values agroo
well with the obsorvcnl except at 45 weight per cent which in
beyond the concentration corresponding to zero fluidity, an shown
in Table LVI. Bottazzi and d'Krrico give their viscosities an
times of flow, which of course are not proportional to the V!H~
coHitioH, as is HO often assumed, HO this may perhaps explain the
discrepancy between the two viseomctors. But more1, work
needs to be; done on this subject to definitely establish whether
the viscosity of a suspension is independent of the*, dimensions
of the instrument or not. At any rate then; in no evidence that
the fluidity of concentrated HUpennionH Is abnormally low. In
fact those experiments lead to the opposite conclusion.
TAIILK LVf,—••• THK Px,uti>rnKH or OLVCOCIKK HUHPHNHIONK AT 37°C5

Per c«»nt glycc»g<*n 1
hy weight
t>

j Fluidity calo.u-

Fluidity ohm^rvfuii latfid by fonnuln
\ (7!)

0
144.0
144

1
138 0
139
Vi«eomc4c»r No. 1

5
114.0
118
yn - 144,0

10
KILO
92
t - 27.6

16
(WU)
fill

20
40.0
40

20
40 0
40

25
32 0
»4
VincoincUir No. 2

30
20 0
21
v\ 77.0

35
12.0
11
c *•> 41.0

40
5.0
2

45
2 3