Prof. Norton on the Analysis of the Oat. 319 
Composition of Ash from Chaff of Hopeton Oat, from Mr. 
Harbottle, Hexham, Northumberland. . 
Taste XXII. 
Per-centage, 
ulphuric acid, . ‘ ; E ied : : 5°32 
Chlorid of sodium, (common salt,) . i ‘ ; 511 
Potash, ? ; ; , ‘ . ; . 7:96 
Soda, ; : . ; ; 2 ‘ é 
Phosphates of lime, magnesia, and iron, . 3 . 5-84 
Lime, Sicily te tentinn week S Rsilig? 4-55 
Magnesia, . : : ’ ; ‘ ; va as 1-84 
Soluble silica, . ‘ ; i : : ‘ : aioe 
Insoluble siliea, . : A ‘ : ‘ Pgh ee 56-05 
98-66 
The quantity of silica in this ash amounts to nearly 70 per 
cent., being much greater than in any ash that I have before 
instanced. There is an extraordinary quantity of soluble silica 
in this chaff, and it may probably in this respect be considered an 
extreme case, for I have not found so much in any other sample.* 
The office of the chaff seems to be to protect the oat during 
the earlier stages of its growth. For this reason fully one-sixth of 
its weight is ash, and of this ash 70 per cent. is silica. While the 
husk is yet soft and green, the chaff has arrived nearly at matu- 
nity, and closely envelops the tender seed with its flinty covering. 
As the husk gradually hardens, the chaff unfolds, and at last 
leaves the grain entirely to this its ultimate protector. 
Composition of Ash from four specimens of Chaff. 
Tasre XXIII. 
Hopeton Oats. Potato Oats,|Dun Oats, | 
No.1. Light|No. 2 Pooi} Gravelly | Good 
Barley soil.| Moss. soil. loam. 
Salts soluble in water, chiefly sulphates 
Rene sega PEL Ae QF a 3502 | 34-12. 8 
Phosphates of lime, magnesia and iron 4:29 Fe 3 
Limeand magnesia, ... .. . | 4:03 | 714 | 7-01 | 4-44 
es oath. 6°65 
56 Bond 
99-99 | 100-00 | 99-99 | 100-00 
a aE SRN ey es 
to burn and weigh, before treating with acid, that portion of the watery solution 
which refused to redissolve after evaporation to dryness ; but latterly, fearing that 
be formed insoluble even in strong acid, 
ht 
added the acid to the undissolved portion before burning. 
