TRANSACTIONS OF THE SECTIONS. 35 
lution is evaporated to dryness to separate sand and charcoal and the silica of the ash. 
The silica is dissolved out from the former impurities by dilute solution of caustic alkali, 
_ and estimated in the usual manner. The sand and charcoal are also weighed. The 
solution of the ash is now divided by measure into four equal portions. From one 
portion peroxide of iron, lime and magnesia are obtained. In a second quantity the 
phosphoric acidis estimated. In athird the alkalies, potash and soda are found, and 
the fourth is reserved. 
Estimation of Peroxide of Iron, Lime and Magnesia.—The determination of the 
oxide of iron is indirect; it is obtained by throwing it down in combination with the 
phosphoric acid of the ash. To the acid solution (partly neutralized by ammonia) 
acetate of ammonia is added in the cold, phosphate of iron precipitates, is collected 
and weighed; 100 parts contain 56-08 parts of peroxide of iron. The filtered liquid 
affords lime by treatment with oxalate of ammonia (the acetic acid reraaining in ex- 
cess), and magnesia by the subsequent addition of phosphate of soda and ammonia. 
Second portion. Estimation of Phosphoric Acid.—The estimation of the phosphoric 
acid is also indirect. A portion of clean iron wire is weighed out and dissolved in 
nitric acid. The solution is added to that of the ash, and the whole is partially neu- 
tralized by ammonia. Acetate of ammonia is added, and the liquid is brought to the 
boiling-point. A precipitate of phosphate and peroxide of iron (which is of a buff- 
brown colour, provided the iron is in proper excess) is obtained. ‘his is collected, 
burnt and weighed; the phosphoric acid is calculated by subtracting the weight of 
_ peroxide of iron originally present in the ash, and that to which the metallic iron added 
is equivalent ; it sometimes happens that a little iron remains in the liquid; this must 
be thrown down by ammonia, collected separately on a small filter, and its weight 
added to that of the former precipitate previous to the calculation. 
The alkalies are obtained (from the third portion of liquid) precisely as recom- 
mended by Will and Fresenius. For the estimation of the chlorine and sulphuric 
_ acid, a separate portion of ash is dissolved in nitric acid, and precipitated successively 
by nitrate of barytes and nitrate of silver. 
In the statement of the analyses, the chlorine is always apportioned to the sodium 
of the soda found, or in default of this to its equivalent quantity of potassium. (See 
_ Dr. Daubeny’s paper.) From the constant use of this process during a period of six 
_ months spent in the analysis of the ashes of plants, the author recommends it as by 
_ far the most easy of execution and satisfactory in its results of any at present em- 
_ ployed. 
4 
OS en a 
i ee 
Observations on the Ashes of Plants. By Professor Jounston. 
On the Ashes of Oats. By J. P. Norton (Connecticut, United States). 
_ _ The following are the results of numerous analyses made during the past year by 
the author :— 
_ 1. The quantity of ash varies in different parts of the same plant. I have divided 
_ the plant into seven portions,—the grain, the husk, the straw at three different heights, 
_ the leaf, and the chaff. I give the extremes of my trials with numerous samples. In 
_ the grain the per-centage ranges from 1°81 to 2°32; in the husk from 5:27 to 7-11; 
in the top straw from 4:95 to 9°22; in the middle straw from 4-23 to 7-89; in the 
bottom straw from 5:18 to 9:76; in the leaf from 7:19 to 14°59; in the chaff from 
6°71 to 18:59. I do not give these as the true extremes, but merely as the extremes 
_ of my trials. I have not found that regular gradation from top to bottom which has 
__ been observed in wheat and rye; there seems to be no general rule. These ashes 
are of course all calculated dry, and no per-centage ever considered to be ascertained 
~ until three or four trials agreed. 
_ _ 2. The quality of the ash varies in the several parts of the same plant. This is 
_ shown by instances from a table of the composition of one of the samples which I have 
_ analysed. ‘The ash from the grain contains 49°24 per cent. of phosphoric acid, 31°15 
of potash and soda, 13-93 salts of lime and magnesia, 0°80 of soluble silica, 0°93 of 
‘insoluble silica, &c. The ash from the husk has very little phosphoric acid, but 11:61 
_ of sulphuric acid; potash and soda 7:41; lime and magnesia 2°33; while the soluble 
_ Silica is 5°46, and the insoluble 68°39. 
ey D2 
