a 
‘ 
Correspondence of J. Nickles. 103 
chlorid of Bonwoy! and benzoate of soda combines at a tempera- 
ture of 130° C., to form a limpid solution, and it is only on rais- 
ing the temperature that the precipitation of sea-salt indicates the 
commencement of that decomposition which yields at the same 
time anhydrous benzoic acid * It is ouly when looked upon as 
a momentary combination followed by a decomposition, that the 
theory of double al ai becomes intelligible, aud in ac- 
cordance with known facts 
From the narrow limits of temperature which often inelnde 
the two processes, and from the ease with which light, warmth, 
friction and pressure excite the decomposition of such bodies as 
the chlorid of nitrogen, the nitrite of ammonia, the oxyds of 
chlorine, and the metallic fulminates, we may couceive that 
within still narrower limits, and under conditions as yet unde- 
fined, many bodies may exhibit affinities for each other, which 
are reversed by avery slight change of condition. In this way 
we may explain many of those obscure phenomena hitherto as- 
cribed to action by presence or catalysis. 
Montreal, Nov, 10, 1854. 
Art. XIV.—Correspondence of M. Jerome Nicklés, dated Paris, 
Nov. 3, 1854. 
Odituary.—The patriarch of French Botanists, a Brisseau = Mirbel, 
has j just died at an advanced age. For many vears he had been dead 
to science as well as to his family and friends, He. came out, tke many 
others illustrious in science, during the French Revolintion, and w 
active in promoting the progress of the Scien nce of seperti at the com- 
e 
of the microscopic anatom my of plants. The microscope which more 
than a century before had furnished important results to Grew and Mal- 
pighi, had long been left, in France especially, among a appara- 
M. 
tus, and was hardly applied to the Natural Sciences. irbel, 
engaged in this fertile line of research, with very imperfect instruments, 
and from the commencement of his investigations in 1801, aimed t 
found the department of the comparative anatomy of plants, by siudy- 
ing for this object a number of families of acotyledonous and monoco- 
tyledonous plants. 
In early youth he devoted himself with success to painting, and w 
intimately acquainted with the celebrated artist Girard. His kn owl- 
edge of painiing was afterwards of great use to him, tiga him to 
; ro etch well what he observed, as may be seen especially in his re- 
Searches on the structure of the seed and embryo of different ‘aie of 
the family of —_ alm, etc. 
- Mirbel w member of the Academy of Sciences from the year 
180s. His irk nite « Eléments de Botanique” in 1815, led to his 
* Gerhardt, Ann. de Ch. et de Phys. 3me Serie, tom. xxxvii, p. 299. 
