598 Philippine Journal of Science 1920 
TABLE 6.—Analysis of starch and flour by the Munson and Walker and 
the alkaline potassium permanganate methods. 
| 
| | ‘: , 
| \Alkaline potassium 
—- — emma permanganate 
z | method. 
Sam- | 
ple : Name of sample. 
No. Direct Direct 
acid hy-| Saliva | acid hy-| Saliva 
drolysis | method, | drolysis | method. 
method. method. 
Per cent.| Per cent.| Per cent.| Per cent. 
We ons eels asec pe Se es ek 10) 130i 90:96 Fosc22. 
2 Os oa oo ee oe cack 19:08 ja 90,89 4 oo. eink. 
3 Dee De et Sane che vaca wade 5 HRY @ Is (ORO ies $2, 96: 1. to sa 
4 Re ee (ey eerie 16,18 [Sates 
b PReanGN BtAken fe ? 73:06 |e eee 
6 i ee a ce oS Pe 2 peeerie 4 eae 
7 hs eS he er TE Uh ie 18. OF. | yas nsces 
8 Ds seks acy! ooh me ain eae Se seee 74 | 3a iho een TTR | osgeeeees 
9 BIG ee eC peace oe ea Eee Sh (eee ee vA: eens eS 
10 Wa oes be ea sd 98.00 [io 18: OB oe 
Tid Areawrsot tout a 77.79 | Eee ee 64.00 ce 
12 | Dee ie es ee | 78. 90 68.83 | 84.04) 70.39 
78.1) Wiese four Se re Se ee fo ee 70:96:15 sistigsas 1G: GR | ose ee | 
34) Banank font. o. S056 6 si a es 56. 88 | Patiala? 66.15 $c eee 
15 | Dioseorea d i Se a oe 56.88 | 45.21 68.28 | 45.32 
46:|Deostoren alata flour. .u.< ise. 2 55. o seco cle 66.49 | 60, 13 72.86} 59.89 
permanganate in a volume of 100 cubic centimeters, 0.2 N alkali 
is found to be the concentration most favorable for the oxida- 
tion of glucose, the extent to which this sugar is oxidized declin- 
ing when the concentration of alkali is changed from this point. 
In the case of 0.1 N potassium permanganate, there are two 
concentrations of alkali most favorable for the oxidation of 
glucose; these are 0.6 N and 0.2 N. The results obtained in 
these experiments on the concentration of alkali most favorable 
for the oxidation of glucose by potassium permanganate agree 
with those of the previous work on the subject.. The amount 
of potassium permanganate used increases uniformly with in- 
creasing amount of glucose from 1 to 40 milligrams only when 
the concentration of alkali is 0.04 N. This is the main reasoD 
for choosing this concentration of alkali, for with it more ac 
curate and consistent results and a wider rarige of concentration 
of glucose can be obtained. One-tenth N potassium permanga 
nate was chosen in preference to 0.2 N because it was thought 
that the former concentration would have less power to oxidize 
organic substances other than glucose when the method is ap- 
plied to agricultural products, and it will surely give more a© 
curate results. 
