of the fixed Alkalies . 19 
necessary that a large quantity of the oil be employed. On 
the fluid fixed oils it produces the same effects, but more 
slowly. 
By heat likewise it rapidly decomposes the volatile oils ; 
alkali is formed, a small quantity of gas is evolved, and char- 
coal is deposited. 
When the basis of potash is thrown into camphor in fusion, 
the camphor soon becomes blackened, no gas is liberated in 
the process of decomposition, and a saponaceous compound 
is formed ; which seems to shew that camphor contains more 
oxygene than the volatile oils. 
The basis of potash readily reduces metallic oxides when 
heated in contact with them. When a small quantity of the 
oxide of iron was heated with it, to a temperature approaching 
its point of distillation, there was a vivid action ; alkali and 
grey metallic particles, which dissolved with effervescence in 
muriatic acid, appeared. The oxides of lead and the oxides of tin 
were revived still more rapidly ; and when the basis of potash 
was in excess, an alloy was formed with the revived metal. 
In consequence of this property, the basis of potash readily 
decomposes flint glass and green glass, by a gentle heat; 
alkali is immediately formed by oxygene from the oxides, 
which dissolves the glass, and a new surface is soon exposed 
to the agent. 
basis of potash on the oils. Some anomalies occurred which led to the inquiry, and the 
result was perfectly conclusive. Olive oil, oil of turpentine, and naphtha when decom- 
posed by heat, exhibited as products different proportions of charcoal, heavy inflam- 
mable gas, empyreumatic oily matter, and water, so that the existence of oxygene in 
them was fully proved ; and accurate indications of the proportions of their element!? 
might be gained by their decomposition by the basis of potash. Naphtha of all fur- 
nished least water and carbonic acid, and oil of turpentine the most. 
D 2 
