On the Propagation of Sound. 201 
great number of works, and no person has hitherto called the fact 
in question. 
Having occasion annually to make a quantity of sulphuric 
ether, I have always remarked that the mixture of equal parts of 
alcohol and sulphuric acid becomes milky, and deposits a white 
crystalline powder. 
With a view to collect this crystalline deposit, I mixed the li- 
quids in a large flask, and | decanted it after a few days in order 
to proceed to distillation. 
After having preserved the precipitates for several years, I 
mixed them together in order to subject them to an ulterior ex- 
amination. 
This powder, when mixed with some fine needle-formed cry- 
stals, being dried with a gentle heat, had an acid taste, owing to 
a little sulphuric acid which was interposed, and which I took up 
by washing with alcohol. This alcoholic liquor contains merely, 
as I have said, sulphuric acid, and not a trace of oxalic acid. 
The powder when thus washed was perfectly neutral: it did not 
even contain any substance of the organic kingdom; for, when 
heated in a retort, it is not carbonised, and no gas is extricated. 
Boiling water dissolves a small quantity, and this solution is turbid 
with oxalate of ammonia, as well as by the muriate of barytes. 
The white residue, insoluble in boiling water, immediately becomes 
black on placing it in contact with sulphuretted hydrogen, or 
rather with the hydrosulphuret of ammonia. 
I pass over other details of experiments ; for it is easily seen 
that the crystals, which are deposited from a mixture of equal 
parts of sulphuric acid and alcohol, are nothing else than a com- 
pound of sulphate of lime and sulphate of lead*. 
XLI. The Propagation of Sound, according to the Newtonian 
Theory, demonstrated ;—with Remarks on the one advanced 
by La Piace, and other Observations. By RicHarD WiNTER. 
Whitby, March 15, 1814. 
Sirs, Tue theory of the propagation of sound through the atmo- 
sphere, is a problem that has engaged the attention of mathema~- 
ticians and philosophers of the first celebrity ; but the great dif- 
ferences deduced from the most accurate observations of experi- 
mentalists, and the investigations of mathematical theorists, have 
almost rendered the researches of modern philosophers hopeless 
of acquiring the truth frdm theory alone. 
We shall merely notice a few of the many observations which 
have been made to determine this problem. 
* A mixture of twenty pounds of alcohol and sulphuric acid gave only 
25 grains of this dried powder, 
The 
