MAKING CARBORUNDUM IN THE ELECTRIC FURNACE
At the end may be seen the attachments for the wires carrying the electric current and on the side the flames from the burning carbon.
The temperatures attainable with various fuels in the compound blowpipe are said to be:
| Acetylene with oxygen | 7878° F. |
| Hydrogen with oxygen | 6785° F. |
| Coal gas with oxygen | 6575° F. |
| Gasoline with oxygen | 5788° F. |
If we compare the formula of acetylene, C2H2 with that of ethylene, C2H4, or with ethane, C2H6, we see that acetylene could take on two or four more atoms. It is evidently what the chemists call an "unsaturated" compound, one that has not reached its limit of hydrogenation. It is therefore a very active and energetic compound, ready to pick up on the slightest instigation hydrogen or oxygen or chlorine or any other elements that happen to be handy. This is why it is so useful as a starting point for synthetic chemistry.
To build up from this simple substance, acetylene, the higher compounds of carbon and oxygen it is necessary to call in the aid of that mysterious agency, the catalyst. Acetylene is not always acted upon by water, as we know, for we see it bubbling up through the water when prepared from the carbide. But if to the water be added a little acid and a mercury salt, the acetylene gas will unite with the water forming a new compound, acetaldehyde. We can show the change most simply in this fashion:
C2H2 + H2O → C2H4O
acetylene added to water forms acetaldehyde
Acetaldehyde is not of much importance in itself, but is useful as a transition. If its vapor mixed with hydrogen is passed over finely divided nickel, serving as a catalyst, the two unite and we have alcohol, according to this reaction:
C2H4O + H2 → C2H6O
acetaldehyde added to hydrogen forms alcohol