Agricola

AGRICOLA, Georgius. (Born: Glauchau, Saxony, Germany, 24 March 1494; Died: Chemnitz, Saxony, Germany, 21 November 1555.
From 1518 to 1522, Agricola studied medicine and chemistry at Bologna, Venice and Padua. He then taught the classics at the Municipal School, Zwickau, Saxony. In 1527, he moved to Joachimsthal, Czechoslovakia, where he opened a medical practice. In this locality, with the mining activities of the surrounding area impacting his daily life, Agricola began to study mining techniques and mineralogy. After an appointment in 1533 as official historian for the principality of Saxony, which included an annual stipend, Agricola moved again. He relocated his medical practice to Chemnitz in Saxony. There he became a civic leader which lead to his being elected mayor of the town in 1546, 1547, 1551, and 1553. Agricola was one of the extraordinary scientists of his age. His texts on medical diseases suffered by miners were innovative for the time, and for his works that dealt with mining and mineralogy, he was known “The father of mineralogy” by no less than Abraham Gottlob Werner.

De Re Metallica Dialogus is Agricola’s first published work in relation to mining. The text of this work is in the form of a dialogue between “Bermannus,” who is described as a miner, mineralogist, poet, and student of mathematics, and “Nicolaus Ancon” and “Johannes Neavius,” both scholars and physicians. The main theme of the dialogue is the correlation of minerals mentioned by the ancient authors and those found in the Saxon mines. The three conversationalists wonder through the mines and discuss matters that come to their attention. There is no systematic or logical arrangement to the text, therefore. Occassionally, statements of historical or technical interest are included.

De Natura Fossilium in ten books is Agricola’s most important statement on mineralogy. In this work, Agricola approached the study of mineral substances in a naturalistic way. He rejected many myths associated with gems, and the system of classification that is inferred from his writings exhibits degree of generalization not found in earlier handbooks. It is often considered the first attempt at systematic mineralogy, the minerals being grouped into (1) earths, like clay, ochre, etc., (2) stones like gems, semi–precious and unusual as distinguished from rocks, (3) congealed juices like salt, vitriol, alum, etc., (4) metals and (5) compounds being homogenous mixtures of simple substances and forming minerals like pyrite, galena, etc. Agricola applied physical properties such as solubility, fusibility, odor, taste, color, etc to distinguish between mineral varieties. He describes several varieties of earth, and arranged the descriptions according to the purpose for which they were used. Thus he speaks of earths used by farmers as different from those used by potters, sculptors, painters and physicians. This demonstrates that he had an awareness of problems connected with the classifying of similar substances. Agricola was a practical man and his great contribution was to mineral description. He codified much of the ancient knowledge, but in the case of theoretical mineralogy developed no new insights. References in contemporary books show that soon after Agricola mineralogical works were published, they were being cited as leading sources.
Book I describes the characteristics of minerals such as color, brillance, taste, shape, hardness, etc.
Book II describes the earths and Book III reviews the minerals made of congealed juices, and includes salt, soda, potash, saltpetre, alum, vitriol, orpiment, etc. Book IV treats camphor, bitumen, coal, amber, etc. Book V covers lodestone, bloodstone, gypsum, talc, asbestos, mica, geodes and various fossils, flourite and quartz. Book VI treats gems and other precious stones.
Book VII in on rocks like marble, serpentine, onyx, alabaster, limestone, etc. Book VIII covers metals, while Book IX describes various furnace observations such as making brass, gilding, tinning and furnace products like slag, copper flowers, etc. Book X covers compounds that embrace the description of a number of recognizable silver, copper, lead, quicksilver, iron, tin, antimony and zinc minerals.

De Re Metallica is the first systematic treatment of mining and metallurgy and one of the most important technological volumes published in the sixteenth century. Written by Agricola over the course of 20 years, the manuscript was probably completed by 1550; however, the hundreds of woodcut used for illustration delayed publication until after Agricola’s death. Everything known by Agricola concerning mining and metallurgical techniques is contained therein, including sections on prospecting, mine construction and administration, procedures for the manufacture of glass, alum and sulfur. The volume is further enhanced by the inclusion of two hundred and seventy-three magnificent, large woodcut illustrations by Hans Rudolf Manuel Deutsch depicting a large variety of mine and refinery processes, including water powered pumps, ore haulage, mine ventilation, furnace stoking, ore transportation, etc. A large number of minerals are mentioned by Agricola, including many like bismuth for the first time. In addition, the mining and metallurgical processes described and illustrated are still at there core used even today. Also included are the author’s last statement in Book V of physical geology, including his theories of the influence of water and wind on the shaping of the landscape, and a rather clear account of the stratification of rocks he saw within mines.

Agricola's Classification

The materials considered are fossilia, that is, extractible materials, minerals, rocks, fossils.
Agricola states his classification on a series of objective external properties of the materials : colour, weight (i.e. specific weight), transparency, glitter, taste, smell, shape, texture, hardness, friability, roughness solubility, fusibility, fragility, cleavage, combustibility.
He gives the description of the uses and origins, and of new minerals, of the genetic hypotheses, and of the metallurgic processes.
There is no distinction between minerals and rocks, between homogenous and heterogenous, or between composites and mechanical mixtures (cf. mixed and composites).

1. SIMPLE FOSSILS

a. TERRAE (argilla, creta, terra medica)

b. SUCCI CONCRETI I. (sal, nitrum) II. (alumen) III. (sulfur, bitumen) IV. (alumen)
V. (chrysocolla,aerugo,auripigmentum)

c. LAPIDES I. COMMUNI (magnes, haematites, aetites) II. GEMMAE (adamas, smaragdus, carbunculus)
III. MARMORA (porphyrites, ophites, Parium) IV.SAXA (arenarium, calcarium)

d. METALLA I. (aurum, argentum, plumbum) II. (ferrum) III. (argentum vivum)

2. MIXED AND COMPOSITE FOSSILS

a. LAPIS et SUCCUS CONCRETUS

b. METALLUM et TERRA

c. LAPIS et METALLUM in partibus aequa libus

d. LAPIS et METALLUM abundans

e. LAPIS abundans et METALLUM

f. LAPIS et METALLUM et SUCCUS CONCRETUS

An explanation of the various terms used by Agricola :

Terrae (earths) are materials that become plastic.

Succi concreti (concrete substances, i.e. salts), which dissolve or soften in water.

Lapides (stones) do not grow soft in water ; they turn to powder of melt in fire.

Marmora (marbles) : polishable stones

Metalla (metals) are liquid (Hg) or become liquid (Au, Ag, Pb, Sn, Cu, Bi), or grow soft (Fe) in fire.

Misti (mixed) are formed by diverse bodies which are intimately associated to form a new material, and can only be separated by fire (galena, schists, bituminous or copper).

Compositi (composites) : diverse bodies, recognizable with the eye, separable by hand or by water (gold-quartz association, conglomerates)