by Christian Huygens. 47 
arbor lies horizontal, and the pendulum takes the place of a per- 
pendicular balance. Mr Berthoud seems to have founded his 
view of the subject only on a comparison of the latter. The 
simplicity, too, of the alteration, is rather a proof of ingenuity, 
especially when we remember that improvements on clocks and 
pendulums were a favourite theme with the learned at that 
time. 
Notice respecting Plate I. Fig. 5, and 6. These figures are 
intended to represent the rude sketches sent to Huygens from 
Florence, through the medium of his friend Bouillau at Paris, 
and of which complete Jac similes are added to the original 
memoir. Those here, given, without pretending to the same 
exactness, are tolerably accurate copies, being reduced to nearly 
p or to between one-third and one-fourth of the linear dimen- 
sions. — - Translator. 
Art. Inquiries into the Laws which are observed in 
the Distribution of Vegetable Forms. By Baron Alexan- 
der Humboldt * **. (Continued from Vol. VI. p. ^89.) 
It is with the distribution of organic beings as with all the 
other phenomena of the physical world. In the midst of appa- 
rent disorder, which seems to arise from the influence of a 
multitude of local causes, we discover the immutable laws of 
Nature, as soon as we cast our eyes over a great extent of coun- 
tryj or employ a mass of facts with which the partial disturb- 
ances mutually agree. I have had the satisfaction to see this^ 
work completed by a minute examination made in Germany, 
England, Italy, and of late in Denmark. One of the great- 
est botanists of our times, and indeed of any age, Mr Ro- 
bert Brown, has compared each of the numerical results with; 
those given by the rich herbaries which he has had the oppor- 
tunity of GonsultiUg. Many of the numbers have been rectified,, 
while the others have been confirmed by an agreement some- 
* This continuation is taken from a Memoir read before the Academy of 
Sciences on tlie 19th February 1821. 
