On Water-W heels. . 97 
Substances, and in no other instance can one be procured front 
‘water without the correspondent quantity of the other, or w:th= 
out some product in which the other may be supposed to enter.” 
The French chemists have introduced innumerable errors into 
science, by drawing false conclusions from their experiments. 
When they saw that, in burning together id grains of in- 
flammable air, and 85 of vital air, they obtained exactly 100 
grains of water, they concluded that water is a compound of 
those two gases. But light and heat were produced in their ex- 
periment, as well as water: but thesé phenomena escaped their 
notice ; and this oversight might lead them to form an erroneous 
hypothesis. Since nothing that is inflammable ean be procured 
from pure water by any means yet discovered, it follows of 
course that the elements of combustion must first be put into 
water before those two gases can be obtained, which are sup- 
posed to be its component parts. ; 
Now, when a Leyden phial is discharged through the air, 
light and heat are produced ; but when it is discharged through 
water, two gases are formed by taking up a portion of it, which, 
by a certain modification, constitutes their ponderable basis. 
And an electric spark being passed through a mixture of these 
gases, combustion is produced ; for, the elements contained in 
them and in a charged Leyden phial being the same, the effects 
in both eases are produced by the same cause. 
From these incontestable facts it appears, that the authors of 
the new theory mistook the formation and decomposition of the 
two gases, for the decomposition and recomposition of water. 
And as this false hypothesis has gained so much ground in Eng- 
land as to be received as a chemical axiom, every correct ex- 
periment ought therefore to be brought forward, that tends to 
refute an erroneous opinion which retards the progress of true 
science, ! 
Lynn, Jan, 26, 1816. EzEKIEL WALKER. 
[To be continued.] 
XX. On Water-Wheels applied in propelling Vessels in Navi 
gation. 
To Mr. Tilloch. 
Sir, — a practice of navigation by the rotary movement 
of wheels having excited the attention of public authorities, as 
well as of private individuals, perhaps you will allow the fol- 
lowing suggestions to he made known to the readets of your 
agazine, 
Vol. 47. No. 214, Feb. 1816. G Let 
