MEMOIR OF LAMARCK. 29 
to instruct others, and ultimately to produce works 
which will form a lasting monument to his fame. 
Before engaging in the study of practical zoology, 
Lamarck had rendered himself conspicuous by the 
boldness and originality of his speculations regarding 
a variety of physical phenomena. The general laws 
of chemistry, the origin of the globe and its inhabi- 
tants, the condition of the atmosphere and of living 
bodies, and most other great questions fitted to 
attract an active fancy, had by turns been the 
subjects of his contemplation ; and on many of 
them he had elaborated a theory which he conceived 
calculated to elucidate the most abstruse phenomena 
they presented. To these views he attached the 
highest importance, considering them destined to 
place almost every branch of knowledge on a new 
and secure foundation. lie therefore took advan- 
tage of every opportunity to enforce and illustrate 
them, and they will be found to pervade most of 
his published works, even such as afford no obvious 
plea for their introduction. Although most of 
them are exploded as fanciful and untenable, these 
theories display much ingenuity and extensive know- 
ledge, and a pretty full account of them is necessary 
to show the character of Lamarck’s mind, and the 
wide range of his studies. 
As early as 1780, he had presented his Theory of 
Chemistry to the Academy of Sciences ; but it was 
not published for several years afterwards, when it 
appeared under the title of “ Researches on the 
Causes of the most important physical Facts, and 
