58 Analysis of the Protogea of Leibnmitz. 
- the means of draining them. What was the exact amount of time 
and thought that he devoted to this object it is perbaps impossible 
after an interval of a century and a half to determine. It is probable, 
however, that he was a kind of director or superintendant of mining 
operations in the Hartz, during a considerabie part if not the whole 
of these ten years. In an application made by him for a post in the 
service of the Emperor in 1680 or ’81, he stated that his attention 
was much occupied with this business, which however he then hoped 
would be finished, so far as he was concerned, in the course of a few 
months. The mountains are about forty miles from Hanover. He 
had evidently made himself familiar, by personal observation, with 
the whole district of the Hartz, and with all the processes of mining 
and metallurgy practised there. ‘The appearances presented in the 
mines could hardly fail of leading a mind like that of Leibnitz, to 
some speculations on the causes by which they had been produced, 
and to the composition of a work like the Protogwa. It is from this 
quarter that many of his facts and illustrations are drawn. In 1687 
he went to Italy, to collect materials for a history of the House of 
Brunswick, and when in that country did not neglect the opportu- 
nity that was offered of prosecuting his geological enquiries and ob- 
servations. 
It appears from a passage in the 19th section, that the Protogea 
was composed soon after his return to Hanover, in 1691, when he 
was forty five years of age. Like most of his other writings, it is 
a short tract; such as would occupy a‘space of fifty pages only in 
this Journal. It is illustrated by twelve plates, prepared by the au- 
thor, containing representations of shells, ichthyolites, teeth of mam- 
mifere and other organic remains. A “schediasma” or abstract of 
the work, (how full I am unable to say, but it is spoken of as con- 
taining only “ primas lineas”—a mere outline,) was inserted by Leib- 
nitz in the Leipzic Acta Eruditorum, for January, 1693. The Pro- 
toga itself then lay in manuscript till 1749, thirty three years after 
his death, when it was at length published, with a dull impertinent 
preface, half as long as the work to which it is attached, by Scheide. 
From the manner in which the abstract in the Acta Eruditorum is 
referfed to, in two or three places in his letters, it may be conjectured 
that the author thought well of his performance, and felt a consider- 
able anxiety to learn the opinions of others respecting it. 
The Protogza is divided into forty eight sections or chapters, of 
which the first five, after the introductory one, are upon the primeva 
