Portrait of William Henry (1765 – 1836) English Physicist and Chemist; Stefano Bianchetti.

William Henry, M.D., (1774-1836) an English chemist, beginning in 1803 published results from an extensive series of his experiments on various gases and their solubilities, partial pressures, and other properties when these various gases are in contact with various liquids. His results were published along with a series of his chemistry lectures in at least eight editions including Volume I Eighth Edition in 1818 by The Royal Society of London (1) of which Dr. Henry was a fellow. Henry’s work was reviewed by Mr. John Dalton, (1766-1844) English chemist, physicist and meteorologist, famously renown for his atomic theory including today’s method for establishing atomic weights for the chemical elements, and Dalton’s Law of partial pressures.(2) The Dalton (Da) in The International System of Units (SI) is named after John Dalton; one Dalton is defined as an atomic mass equal to one twelfth of the mass of a neutral carbon atom, which is equal to one hydrogen atom. Dalton and Henry were not without opposition. English Scientist Dr. William Hyde Wollaston (1766-1828), also a Fellow of the Royal Society of London, and Irish mathematician Dr. James Thomson, (1776-1849) father of famous scientist William Thomson Lord Kelvin, and Swedish scientist Professor Baron Jöns Jacob Berzelius (1779-1848), on the other hand, asserted oxygen as the decimal unit of atomic weight and reviewed the works of both Dalton and Henry.

“The principle, on which gases are absorbed and retained by liquids, is still a subject of controversy. By Berthollet, Thomson, Saussure, and the generality of chemists, it is ascribed to the exertion of a chemical affinity between the gas and the liquid; but it is contended by Mr. Dalton and myself that the effect in most cases is chiefly, if not wholly, mechanical.”

As discussed in the following paragraphs, Dalton and Henry held against their contemporary critics that the principle was mechanical, that is the principle is physical, not chemical. They demonstrated by ingenious experiments and reports by others to their scientific critics, for example:

“The general inference from his [i.e. De Grotthus’] experiments is, that the intensity of electric light is always in a direct proportion to the density of the gas, and in the inverse proportion to the conducting power of the gas for electricity.”

“The comparative soniferous properties of the gases have been determined by Messrs, Kerby and Merrick; but as these belong rather to mechanical than to chemical science, I shall content myself with referring to the account of them in the 27th and 33d volumes of Nicholson’s Journal, and in the 45th volume of the Philosophical Magazine.” (1) page 134.

Today, misunderstanding of this critical difference between physics and chemistry leads to the ongoing failure to understand and correctly compute the Henry’s Law proportionality of carbon dioxide gas between air and water, with the result that extraordinary and totally unneeded-unnecessary sums of taxpayer’s money worldwide are being squandered in the false belief that humans must reduce atmospheric carbon dioxide concentration. The absorbance of any gas into any liquid and the emission of any gas from any liquid is a physical phase-state reaction, that is, a change in the physical state of the gas, for example:

• its total pressure and partial pressures,
• its temperature and thermal dynamics,
• directional motions and migrations of its constituent molecules
• its volume and density
• the masses and sizes of the constituent molecules.
• the boiling point, freezing point, triple point, sublimation conditions
• specific heat
• opacity

In the bulleted list just above, the identity of the gas nor the amount of the gas changed, and the identity of the liquid nor the amount of the liquid changed. On the other hand, a chemical reaction of a gas and the liquid creates one or more new chemical product entities by changing or combing the reactant entities.

William Henry, confirmed by John Dalton and thousands of other scientists since them, discovered that a gas partitions between a liquid and a volume of gas in contact with that liquid, and that the partition ratio is a physical property like a boiling point or specific heat; these are properties which are not changed by the amount of matter present. Henry demonstrated that the partition ratio is a function of the absolute temperature of the liquid. That is, colder liquids absorb more gas than they emit and warmer liquids emit more gas than they absorb.

In other words, adding carbon dioxide to the atmosphere by burning fossil fuels does not increase the concentration of carbon dioxide in the atmosphere. A carbon dioxide concentration in air which exceeds the Henry’s Law ratio for a given water temperature will be absorbed by water. Any carbon dioxide removed from air will be replaced from water and water containing surfaces everywhere until the Henry’s ratio is restored for the local water temperature. Life evolved under this dynamic condition.

Obituary for William Henry, MD, FRS

“The last name that occurs in the melancholy list of our departed compatriot associates is that of Dr William Henry, to whom the science of chemistry generally and gaseous chemistry in particular, is under great obligation. He was the author of nine papers in our Transactions, many of them of great merit; and his System of Chemistry is one of the best written and best arranged compendiums of that important and extensive science which has been published of late years, whether in our own language or in any other. The Memoirs of the Manchester Society are chiefly indebted to him, in conjunction with Dr Dalton, for the high character which they have so long maintained. Dr. Henry, like Dr. Wollaston, made the results of science, obtained by the most original and difficult researches, the foundation of a splendid fortune, and few persons have contributed more effectually to the promotion of those arts and manufactures which form the foundation of the prosperity of a great commercial nation.” (3)

The elements of experimental chemistry, by Henry, William, 1774-1836. Dedicated to John Dalton (about 47 megabytes in pdf, on file). Here is link for download or reading online: https://archive.org/details/b29329875_0001/mode/2up Experiments on the quantity of gases absorbed by water, at different temperatures, and under different pressures. William Henry. Published:01 January 1832 https://doi.org/10.1098/rspl.1800.0063 and https://royalsocietypublishing.org/doi/abs/10.1098/rspl.1800.0063 2 pages.

III. Experiments on the quantity of gases absorbed by water, at different temperatures, and under different pressures. William Henry. Published: 01 January 1803 https://doi.org/10.1098/rstl.1803.0004. https://royalsocietypublishing.org/doi/10.1098/rstl.1803.0004

Biography of Thomas Henry and his son William Henry. https://www.thornber.net/cheshire/ideasmen/henry.html A biographical account of the late Dr. [William] Henry (PDF), by his son Henry, William Charles, 1804-1892

In Praise of Famous Men – The John Dalton Bicentenary Celebrations, 1966. By Arnold Thackray.
https://royalsocietypublishing.org/doi/pdf/10.1098/rsnr.1967.0006

Dalton’s Unfortunate Choice. by R.W. JONES. (Pdf) https://royalsocietypublishing.org/doi/pdf/10.1098/rsnr.2003.0194 page 18 (Note, John Dalton appointed William Charles Henry, MD (1804-1892) as his biographer. William Charles Henry MD was youngest son of our William Henry MD. Our William Henry MD committed suicide and pre-deceased Dalton).