The Barnes dropping bottle is a small, thick-walled bottle with square sides and a square collar around its mouth. A rubber squeeze bulb with an inserted glass pipette acts as both a stopper for the bottle and a means of dispensing drops of the liquid contained in the bottle. The Barnes dropping bottle holds 30 milliliters of liquid (approximately 1 fluid ounce). Albert C. Barnes (1872-1951), an American physician, devised the Barnes dropping bottle as a means of delivering an accurate dosage of his disinfectant drug Argyrol (a silver-protein compound). The dropping bottle was supplied with a precisely-made glass pipette that dispensed 60 drops/minim as a standardized dosage for non-opthalmic use. For opthalmic application, Barnes also invented an eye dropper that bears his name. Today the Barnes dropping bottle finds wide usage in biological and chemical laboratories, in applications like microscopy and chromatography. It is ideal for any application where a precise amount of liquid must be dispensed drop by drop.