Normal Butane: the 0 °C Cut of the Lightest Gasoline, Distilled Twenty Times in the Cold (Mabery & Hudson 1897)

The lightest gasoline still holds butane, a gas that boils at about 0 °C. Distil it again and again through a condenser packed in a freezing mixture, and the butane gathers as a cut between -2 and 2 °C. Result: 300 grams within -2 to 2 °C, specific gravity 0.6029 at 0 °C, vapour density 2.07 (2.01 calculated for butane). Very little came over below -10 °C. Note: Mabery & Hudson named this cut isobutane. By the boiling points in Ipatieff & Pines, US 2,318,226 (normal butane +0.5 °C, isobutane -10.5 °C), a cut at 0 °C is normal butane, and it is built here as such. Source: Mabery & Hudson, Proc. Amer. Acad. 32 (1897), pp. 101-111. Not given: the freezing mixture, how the butane was stored. Extremely flammable: no flame near. Picture drawn by Youblob.