138 
Following the general idea thus enunciated, the materials collected and at present on 
exhibition in Philadelphia, are divided into two grand divisions, as follows: 
1. Soils and fertilizers. 
2. Vegetable products, the value of which depends upon their chemical composition, 
and the methods for the utilization of which involve chemical processes. ; 
In addition to the materials included in these two grand divisions, the collection 
contains a series illustrative of the various steps involved in the manufacture of butter 
and cheese. wine 
The soils and fertilizers are appropriately grouped, as follows: 
1. Soils from different geological formations. 
2. Known rocks, with samples of the virgin soils formed from them by their disinte- 
gration and decomposition. 
3. Marls—a group which may be subdivided into caleareous or shell marls, green- 
sand marls, and phosphatic marls. 
4, Mineral fertilizers, consisting of phosphatic rocks and limestones. 
5. Vegetable and animal fertilizers. 
6. The combination of the natural fertilizers to produce the manufactured or artifi- 
cial fertilizers and a series of specimens of these products found in American markets. 
The soils from the geological formations of different ages were collected under the 
supervision of Prof. George H. Cook, State geologist of New Jersey, and illustrate 
very fairly the character of the soils common to the sections belonging to the several 
formations represented. 
The second subdivision ‘of soils—those formed directly from disintegration and de- 
eomposition of rocks—consists of a series of virgin soils collected by Prof, E. L. Ber- 
thoud, of Cation City, Colorado, each of which was taken from a large area of known 
rocks with no opportunity of admixture with débris from breaking down of rocks of a 
different character, and they give a fair representation of the soils which these rocks 
are capable of producing, and their consequent agricultural value. Alongside of the 
specimens of soils are fragments of the rocks from which they are formed. 
The marls are rather limited in number, and consist of the varieties named above. 
The greevsand mar] formations are found most extensively in New Jersey, but are by . 
no means confined to that State alone. They may also be found in the recent geologi- 
eal formations of very many of the States of the Atlantic coast south of New Jersey. 
Their value, as is well known, depends upon the potash and phosphate of lime they 
are able to furnish to the soil. 
Phe marls, which are the more numerous of the recent geological formations, but 
which are by no means as valuable as the greensand marls, are the calcareous or shell 
marls, whose value depends almost entirely upon the carbonate of lime in a friable 
condition they contain, and of which they are wholly or iu part composed. 
The third class, which is far more limited with regard to its geographical distribu- 
tion, embraces the phosphatic marls found in vicinity of the phosphatic rock deposits 
near Charleston, S.C. They are taken from different depths below the surface, rang- 
ing from 3 to 56 feet, and contain a fair percentage of phosphate of lime. Their value 
depends upon the percentage of this important constituent, (which varies with the 
depth from which they are taken,) and upon their mechanical condition, which is 
favorable to their removal and application to the soil. They are by no means as yalu- 
able, but are closely allied to the phosphatic rocks spoken of above, which constitute 
the next group. These recks are represented by a series of specimens collected under 
the supervision of Prof. C..U. Shepard, of Charleston, and embrace the two varieties 
known as viver rock and land rock, terms depending upon the immediate locality from 
which they are taken. ‘There is little difference in the chemical composition of these 
two varieties, but there is a marked difference in the color of the rocks, as well as of 
the fossils accompanying them. ‘The color of the river rock is very dark, while that 
of the land roek is quite lig! t, and in the collection these two varieties, with the fossils 
found in connection with them, are so arranged as to illustrate clearly these differ- 
ences. 
The vegetable and animal fertilizers which constitute the next group, while they are 
not as extensive in point of quantity as those already named, are of no less relative 
value. They consist of muck, peat, marsh-weeds, sea-weeds, cancerine, and fish scrap ; 
pork cracklin, dried blood, and other refuse matters from the abbatoirs; and finally, 
of the excrement of bats, large deposits of which are found quite widely distributed in 
caves of many of the inland Southern States, and which bids fair to be a fruitful source 
of fertilizing for the plantations of the South. A complete description of some of 
these deposits, with the results of analyses of samples taken from them, will be found 
in another part of this report. 
The artificial fertilizers are made up by the combination, according to formule 
adopted by the several manufacturers, of the natural fertilizers enumerated. Many 
of those found in American markets, and indeed most of them, are improved by addi- 
tion of materials obtained as by-products of manufacturing processes, or imported 
from other countries. The method generally employed in this branch of manufacture 
