It differs from the simple ketenes in that it is apparently unacted upon by phenols and alcohols.
Three stages in the process are to be distinguished: (i.) calcination, to convert all the metals, except gold and silver, into oxides, which are unacted upon by chlorine; (ii.) chlorinating the gold and lixiviating the product; (iii.) precipitating the gold.
Wohler reduced the sesquioxide by zinc, and obtained a shining green powder of specific gravity 6.81, which tarnished in air and dissolved in hydrochloric acid and warm dilute sulphuric acid, but was unacted upon by concentrated nitric acid.
Soc., April 1894.) At this stage it became clear that the complication depended upon some hitherto unknown body, and probability inclined to the existence of a gas in the atmosphere heavier than nitrogen, and remaining unacted upon during the removal of the oxygen - a conclusion afterwards fully established by Lord Rayleigh and Sir William Ramsay.
In the massive state it is unacted upon by dry air, but if moistened with acidified water, oxidation takes place slowly.