Quackery: 20th. century: 'Improved oxytonor oxygen'
Licence: In copyright
Credit: Quackery: 20th. century: 'Improved oxytonor oxygen'. Wellcome Collection. Source: Wellcome Collection.
Licence: In copyright
Credit: Quackery: 20th. century: 'Improved oxytonor oxygen'. Wellcome Collection. Source: Wellcome Collection.