The crude oil from the Rydal material was boiled for some hours with aqueous potash and the acid of the ester prepared in the usual way. When finally purified it was of a laminated structure and a paraffin-like nature, and melted at 76° C. When titrated with a deci-normal solution of sodium hydrate, the acid gave a molecular weight of 135.6, assuming it to be monobasic. It was a saturated acid, and when treated with manganese dioxide and sulphuric acid gave an odour of benzaldehyde. This evidence points to the acid of the ester being phenylacetic acid. In general appearance and chemical characters it differed from the corresponding acid obtained in a similar manner from the Fagan's Creek material.

The amyl esters occurring in the oil of E. aggregata are thus of particular scientific interest, and worthy of more complete investigation. It is unfortunate that the yield of oil from the species is so small, and the localities where it grows difficult of access.