BULLETIN OF THE BUSSEY INSTITUTION. T5 
The presence of lithium in such appreciable quantity in the coal-ashes 
naturally suggests the idea that this substance may have exerted a hurtful 
influence upon the plants grown in the experiments above recorded. For, as 
is well known, Nobbe, Schroeder and Erdmann * found that chloride of lith- 
ium has a distinctly poisonous action upon buckwheat plants grown by way of 
water culture, that is to say, not in solid soil, but in water to which minute 
quantities of the various kinds of plant-food have been added. But the force 
of the idea is very much lessened, if not wholly destroyed, by a moment’s con- 
sideration of the results of the experiments in coal-ashes as compared with 
those made in the sterile sand, since it appears that the plants in the ashes 
grew as well, when fully fed, as those in the corresponding jars of sand. 
It is not surprising, for that matter, that the poisonous action of lithium 
should be hindered or annulled when this substance is held combined in an 
earthy material like ashes, or admixed with the soil. Even such esteemed 
manures as the ammonium salts are found to act most injuriously upon 
plants when applied in .water culture, unless special precautionary meas- 
ures be taken. 
The water-holding power of the ashes was determined by placing a 
weighed quantity of the material in a weighed funnel loosely plugged 
with cotton-wool, and slowly pouring water upon the ashes, a tea-. 
spoonful at a time, until a drop appeared in the throat of the funnel. 
After standing a little to make sure that any excess of water had 
drained off, the whole was weighed. Under these conditions ashes 
that had been sifted through a sieve carrying four meshes to the 
linear inch took up 95.61 per cent of water; while that which had 
been sifted through a finer sieve carrying twenty-four meshes to the 
inch took up 110.4 per cent of water. 
Before proceeding to determine the power of the coal-ashes to fix 
and hold potassium, sodium, calcium; magnesium, etc., some prelim- 
inary experiments were made to determine the amount of soluble 
silica, and the amount and character of the matters that can be dis- 
* Die landwirthschaftlichen Versuchs-Stationen, 1871, 13, 327. Compare Bir- 
ner and Lucanus, Ibid. 
Tt Compare, for example, the results obtained in jars Nos. 14 and 16 of Series 
D. It is to be remembered, in this connection, that coal-ashes, from their lower 
specific gravity and lack of porosity and mobility, do not afford so good standing- 
room for plants as sand. It has been already stated in the text that plants grow- 
ing in coal-ashes under the conditions of the foregoing experiments are at a certain 
mechanical disadvantage. 
