382 Letter from the Chevalier de Martius to the Editor. 
25. Products of the Combustion of certain Coal Strata.— 
= the neighbourhood of Aubin (Aveyron) there exist certain 
strata, some of which are worked, and others are burn- 
ee having been on fhe for thirty or forty years. It has 
been remarked as singular, that no muriatic acid, or am- 
monia, occurs in the products of this combustion. Much 
sulphurous acid escapes, and various portions of sublimed 
sulphur, and acid aluminous efflorescences have been col- 
lected; but on chemically examining these and other pro- 
ducts sbeained, neither muriatic acid nor ammonia have 
been observe "he coal nevertheless contains an abun- 
dance of senate? and on distillation affords carbonate of am- 
monia. 
¥ * * * Sy eS * = 
26. atone: Hea the Chevalier ue Martins to the Editor. 
- RRMARR 5. css eae ‘ 
“The following letter was received: iit er ipabies” me 
of this number were going to the press. As the Editor — 
is very desirous to promote the laudable wishes of his cor- 
respondent, he publishes the entire letter witb the excep- 
tion of a few passages. 
This course appears to be proper, as the communica- 
tion relates to the interests of science at large —Ep. 
~ Munich, 13th Feb. 1624. 
— 
ING a  ailigeet vusder of your ctepitot Aneel B 
Journal, I cannot but desire to establish an intercourse 
between us, which, I hope, will prove useful both ti yo 
and me. My principal study is Botany, but ! am also 
of Geology, and wish to further these two sciences 
y their mutual influence. Ina tour eh a great part 
: B2 20, | had ion A 
nteresting to the Botanist. I be g you r pe : 
send you two short dissertations on such ae 
ch I consider only as precursors of Pye communica- 
r goons. My friend and companion, Dr. de S aed [pu 
