With the introduction of nitrous oxide for patients undergoing dental treatment, 100% nitrous oxide was usually administered as an anaesthetic. This caused the patient to lose consciousness quickly and could also cause severe hypoxia. In the late 1890s, dentist Samuel Stockton White introduced this two cylinder apparatus, which could administer oxygen with N2O.Early model apparatus with cast iron stand, and two gas bottles. Comes with two canvas gas bags and a detached metal mask and fabric connecting tube.samuel stockton white, nitrous oxide, oxygen, hypoxia