The Collaborative International Dictionary of English v.0.48:

Decene \De"cene\, n. [L. decem ten.] (Chem.)
   One of the higher hydrocarbons, C10H20, of the ethylene
   series.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Diamylene \Di*am"y*lene\, n. [Pref. di- + amylene.] (Chem.)
   A liquid hydrocarbon, C10H20, of the ethylene series,
   regarded as a polymeric form of amylene.
   [1913 Webster]