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190 Bibliography. . — 4 
oxalate of lime into carbonate; note its weight. 6, Add tothe am 
moniacal solution (4) from which the lime has been thrown down 
a 
* 
phosphate of soda—if any precipitate occurs it will be ai in 
magnesia. 7. Now lastly run a current of sulphuretted hydrogen 
through the remaining solution; if manganese is present it will fall, 
and may be reduced to black oxide. rm 
In order to ascertain the existence of alkaline salts, varstieditie 
vegetable matter from another 100 grains, and digest in a little nitric 
acid; dilute and filter, and evaporate to entire dryness ; fuse the re- 
sulting’ salts and add a trifle of prepared charcoal—if any nitrates are 
present, deflagration will ensue, and the alkaline bases will be con- 
verted into carbonates.* Such is the method pursued in the analysis 
of the inorganic constituents of the soil; and we can, from having 
personally spent several weeks in Dr. Jackson’s laboratory, confi- 
dently assert, that no labor or pains was spared in carrying it out in 
every detail, both on the part of himself and his assistants. 
~ As an example elucidating the foregoing, we quote—* The follow- 
ing analysis of the rich alluvium-of the Nile in Egypt, @ soil cele- 
brated from the remotest antiquity for its luxuriant vegetation, wi 
serve asa good example. The analysis was made in my laboratory, 
and under my supervision, by my highly esteemed friend, Benjamin 
Silliman, Jr., who received the soil from Rev. George Jones, U. S.N., 
who took it himself during a visit to Egypt in 1835. I shall give ane 
process of analysis, as an example of our methods. rit 
The soil consisted of the annual layers deposited by the Nile du- 
ring its periodical overflowings. It contained some fine particles of 
mica, deposited between its layers, but was destitute of any pebbles 
orsand. Itisof adeep brownish yellow color, and splits readily 
into thin leaves when dry. The soil having been crushed fine, was 
sifted through a gauze sieve, and no sticks or fragments of rocks were 
found, excepting the fine particles of mica above mentioned. One 
hundred grains of the soil dried at 300° F., lost 7.05 grains, which 
was water. 
“Its vegetable matter was then burned out in the platina crucible, 
placed in a red hot muffle, and the loss was 6.9 grains, which was 
solved, and 68.7 consisted of the insoluble silicates. The 2 ysis 
having been at this stage lost by accident, was renewed, and * 
grains of the soil previously dried at a temperature above that of boil- 
* It will be seen by reference to the analysis of the Nile soil that this methoe 
is not always conclusive, and we cannot doubt if Dr. Jackson had practiced e 
method of Mitscherlich, he would have found more proofs of the existence 
potash in the soils of Rhode Island than he has given them credit for. 
i 
the state of bi-phosphate, 40 per cent. of which may be set down as Ag 
