Editing Wilhelm Ostwald (section)

===Scientific measurements===
As part of Ostwald's investigations in to [[chemical equilibria]], [[chemical affinity]], and [[Acid-base balance|acid-base interactions]], he recognized that many established [[analytical methods]] disturb the chemical systems under investigation. He therefore turned to physical measurements as surrogate methods to understand these important basic phenomena. One such physical measurement is the measurement of the [[viscosity]], or resistance to flow, of a liquid. Ostwald invented a device for this purpose consisting of bulbs that act as reservoirs for a liquid with a capillary, or thin tube, in between the reservoirs.  The time that it takes for the liquid to flow through the capillary from one reservoir to the other is an indication of the viscosity of the liquid.  Using a reference solution, the viscosity of the liquid can be quantified. Ostwald typically used this device to study the behavior of [[solutes]] in water solutions. These devices came to be known as [[Ostwald viscometer]]s and are in widespread use in contemporary times for research and [[quality control]] purposes.<ref name="Sella">{{cite web |last1=Sella |first1=Andrea |title=Classic Kit: Ostwald's viscometer |url=https://www.chemistryworld.com/opinion/classic-kit-ostwalds-viscometer/3004929.article |website=chemistryworld.com |publisher=Royal Society of Chemistry |access-date=5 August 2020}}</ref>

Ostwald designed a pipette that could be used to transfer and measure liquids, especially [[serous fluid]]s. This design was later improved by [[Otto Folin]]. This type of pipette has a bulb at the lower end as a particular design feature. It became known as the [[Pipette#Ostwald–Folin pipette|Ostwald-Folin pipette]] and is widely used in contemporary times.<ref name="Pipette">{{cite web |title=Serological pipets |url=https://www.eppendorf.com/product-media/doc/en/308915/Liquid-Handling_Poster_Serological-Pipets.pdf |website=eppendorf.com |publisher=Eppendorf AG |access-date=11 August 2020}}</ref>