f 
i 
H 
j 
TRANSACTIONS OF THE SECTIONS. 39 
also varies: in No. 1, about 60; in No.3, 45°6; No.4, 75°79; No. 5, 67°59; No. 6, 
37°82; No. 7, 72:05. 
T would now direct attention to some characteristics of the soils derived from the 
decomposition of these slates. Directing our attention to carbonate of lime, that which 
is immediately available, we see a range from 12°50 to 0:83 per cent: then to car- 
bonate of magnesia, there is in one 3:06, and another 0°35. So as to iron and alu- 
mina; in one there is 19°5, in another 4:82. These, with from 1 to 8 per cent. of 
alkaline matter, constitute the soluble portion from which the plant is directly to de- 
rive its support. 
Tn No, 1, then, we have a soil rich in carbonate of lime, with a proper portion of mag- 
nesia and alkalies, its only defect being the large quantity of iron, No.3 has nearly the 
same characteristics, though the lime is much smaller in quantity. In No. 7 there 
is but 0°34 of carbonate of lime, 0:35 of carbonate of magnesia; while in No. 6 there is 
3°33 carbonate of lime, 3:09 carbonate of magnesia, and 12°13 of iron and alumina. 
This soil would obviously in its natural state be very unproductive.. That quantity 
of magnesia might be injurious without lime, and much of the iron was protoxide. 
There is little to hope from the decomposition of the insoluble portion either, for it 
has only 0:17 of carbonate of lime; while there is 3-06 carbonate of magnesia, and 
39°40 of iron and alumina. This is the worst example, though Nos. 5 and 2 are not 
many degrees better. 
These seven slates, then, all picked up within a small extent of country, afford 
seven different soils, varying from very good to very bad. 
The physical state of this section of Wigtonshire is to a great extent unimproved, 
the land being excessively cold and wet; leaving this out of view, however, or rather 
supposing drainage complete the excess of iron, we may see in the variation of the 
per-centage of lime an explanation of many conflicting opinions that prevail respect- 
ing its use as a manure. 
On Mineral Manure. By Professor Lizzic. 4 verbal communication by 
Ernest Dierrensacu, M.D. (of Berlin.) 
After alluding to the varying conditions of soils under the circumstances of geolo- 
gical and geographical position, Dr. Dieffenbach proceeded to point out the advantages 
of using such a compound that it should meet these circumstances ; for instance, that 
for a moist climate it would be necessary so to prepare the saline manure that, al- 
though slowly decomposing to meet the requirements of vegetation, it should not be 
so soluble as to be washed out of the soil by the rains. This is proposed to be effected 
by Prof. Liebig; and having ascertained the mineral constituents removed from the 
soil, it will be the object of the manufacturer to supply their place in the mineral 
manure. It was then pointed out that the manures required for wheat, oats, legumi- 
nous plants and the potatoe must necessarily be different; and the object in view in 
the manufacture of this saline manure is to prepare it with the essential constituents 
for particular crops. 
On Malacca Guano. By Dr. Canter. 
This communication described a peculiar substance, of which recently samples have 
been sent to England. It was stated to be inferior to both the African and the Peru- 
vian, and curiously enough to consist almost entirely of the legs and other indigestible 
parts of beetles. 
On Masses of Salt discovered in the lowest portions of Guano on the Island of 
Ichaboe. By Tuomas J. PEARSALL. 
The salt was transparent and colourless, very soluble in water, and contained phos- 
phoric acid, soda and ammonia, and a trace of some organic matter, which became 
carbonaceous at a high temperature. The salt therefore appears to be a microcosmic 
salt, phosphate of soda, ammonia, and water of crystallization. 
Contributions to the Chemistry of Diabetes. By Joun Percy, M.D. 
In this paper the author communicates the results of nine ultimate analyses of 
human feces, viz. two of the feces in health, six in diabetes, and one in jaundice. 
