1811.) 
_* for doubting the trath of many narrations 
of antient historians, of stones which 
have fallen in Greece, and different parts 
of the world. The melcine stones are 
all of a similar kind, and contain a com- 
bination of earths and metals which is 
found in no other stones; the internal 
evidence from this similarity of composi- 
tion, in all these substances which have 
fallen in Europe, in Asia, and America, 
is perhaps the most satisfactory that 
eould be required with respect to their 
iueteoric production, 
Great weight, or specific gravity, has 
been hitherto considered as one of the 
characteristic properties of metals; but 
this Dr. Davy observed would not apply 
to some of the newly discovered metals. 
Calicum, or the metal from lime; and 
barium, the metal fram barytes, are, like 
sodium and potassium, lighter than water. 
The combustion of manganeée in its me- 
tallic state, and the metals tellurium, co- 
balt, and nickel, was effected by_ placing 
them on a piece of ignited charcoal, and 
passing over them a stream of oxygen 
gas; being the first time these experi- 
ments had been exhibited. ‘Tellurium 
burns with a blue flame, and rises in a 
dense smoke. Cobalt nickel and man- 
ganese burn like iron, throwing out vivid 
sparks, 
_ The acid, known by the name: of oxy- 
muriatic acid, and so important in the 
process of bleaching, has been stated by 
Lavoisier and the French chemists to be 
a compound of muriatic and oxygen ; but 
Dr. Davy asserts that it is a simple sub- 
stance suz generis, not containing oxy- 
gen, but possessing of itself an acidifying 
principle when combined with an inflam- 
mable basis. Muriatic acid is, according 
to Dr. Davy, a compound of this prin- 
ciple with hydrogen, Some of the expe- 
riments exhibited in support of this opi- 
nion are the following: Perfectly. dry 
oxymuriatic acid gas and hydrogen gas 
were burned together without any water 
being produced, which must have been 
the case had this gas contained oxygen. 
The result of this combination is muri- 
atic acid pnly, Phosphorus, and other 
inflammable substances, burned .in_ this 
, yield results very different from come 
rr caip with oxygen, When the alka. 
Mowtury Mag. No, 218, 
qh ti 
Proceedings of Learned Societies. 
457 
lies are heated in this gas, they form 
what are called muriats. ‘The oxygen of 
the alkalies is given out, According to 
Dr. Davy, muriat of soda, or common 
salt, is a more simple substance than 
what is called puresoda; for the muriat 
of soda is the metal of soda, united with 
what is improperly called oxy-muriatic 
gas, but soda contains the metal united 
with oxygen and water. If this opinion 
were true, the class of muriats would"be 
excluded from chemical compourds: 
but we confess we cannot seé any reason 
why muriatic acid, whatever he its con- 
stituent parts, should not be as capable 
of uniting with the alkalies to form a salt 
as nitric and other acids. Many eminent 
chemists are still unwilling to admit Dr. 
_Davy’s conclusions respecting oxymuria- 
tic acid, or what he now calls chlorine, 
from its yellow, colour; and the. question. 
respecting its constituent parts may still 
be considered. as sub judice, Dr. Davy 
hag discovered a new gas, which is formed 
by the union of oxymuriatic or chlorine 
gas with oxygen, their affinity for each 
other is weak. When a stream of nitrous 
gass is passed into this compound gas, it 
unites with the oxygen, and forms nittous 
acid, leaving the chlorine gas unaltered 
in its properties, 
The effect of oxymurjatic acid in 
bleaching he explained by the ainity 
of this gas for the hydrogen of water, 
forming with it muriatic acid, which acted 
on the vegetable fibre; the oxygen of 
the water acting at the same time on the 
colouring matter. ‘The corrosive effects 
of muriatic acid during this process are 
lessened if the oxymuriat of lime be used, 
The oxymuriat of potass is the least pre- 
judicial, but its price will prevent its ap- 
plication to the purpose of bleaching. 
Dr. Davy stated, he had found that the 
oxymuriat of magnesia may be used with 
great advantage; though its bleaching 
property is not so rapid in its operations, 
it is much less injurious than oxymunat 
of lime, which is commonly used. The 
oxymuriat of magnesia will serve re- 
peatedly for the same purpose. If heat 
be applied to it after it has been used, 
the hydrogen is expelled, and it is’ ree 
stored to its former state, 
3N VARIETIES 
