In 1772 Priestley put up a primitive arrangement, constructed entirely of glass, to impregnate water with the " fixed air," derived from the mixture of chalk and vitriol, intending it specially for the use of sailors, and others exposed to "disease of a putrid nature, of which kind is the sea scurvy". He had evidently already seen the great value of the mixture for the preservation and recovery of health. The sketch at foot of preceding page, taken from his works, will give an idea of his arrangement.

Fig. 52.   Dr. Priestley's Apparatus

Fig. 52. - Dr. Priestley's Apparatus.

The process was to be assisted by shaking the bottle (a) as the water became displaced by the "fixed air" The water thus carbonated was to be kept in corked and cemented bottles with the mouth downwards.

He also recommended the use of a "condensing engine" (a pump) to impregnate the water more highly, and recommended powdered limestone or marble and oil of vitriol as the most suitable materials for producing the "fixed air". He also described an apparatus invented by Dr. Nooth for carbonating water.