The First Chemicals

When John Hutchinson relocated to Widnes, he set up home at Appleton Lodge, just alongside the Catholic church of St. Bedes. In fact Hutchinson's tomb lies next to the presbytery, althogh not a Catholic, he was a friend of the local parish priest and provided land for the subsequent construction of St. Marie's Catholic church, now a local community venue near Widnes town centre. Hutchinson died at the age of 40 having established his first production plant at the end of the 1840s for the manufacture of alkali by the Le Blanc process. His first senior appointment was Henry Deacon who will be the subject of my first Local Scientist profiles. Hutchinson's first product was sodium carbonate, also known as soda ash. It is a major component of glass, sometimes called soda glass. Hutchinson and Deacon were both former employees of Pilkington's glass factory in St. Helens. So this was a natural first product for Hutchinson's company.

The image on the left shows the chemical formula of sodium carbonate. Its chemical properties and its applications are discussed below.

Sodium carbonate (and sometimes potassium carbonate) are collectively termed soda ash. This was originally the product of the Le Blanc process in which sodium chloride is mixed with sulphuric acid. The products of this reaction include sodium sulphate which, when fired with coal and limestone generate sodium carbonate. Locally, the collieries of St. Helens provided the coal and the salt came from North Cheshire (you can read an excellent historical and technical account of the salt mines of Cheshire at John P Birchall's web site, together with an account of the development of critical supplies of sulphuric acid).

The succesful outcome of these early chemical processes relied not only on the relative reactivities of the compounds mixed together, but on the temperature of the reaction vessels. The development of processes such as Le Blanc's, were particularly challenging since at the time there were few blacksmiths capable of forging the vessels needed to contain the ofte, highly hazardous reactants. As mentioned above, the demand for large batches of extremely hazardous sulphuric acid, led to the introduction of the so called lead chamber method.

Sodium Carbonate is the disodium salt of carbonic acid and exhibits alkalinizing properties. When dissolved in water, sodium carbonate forms carbonic acid and sodium hydroxide. As a strong base, the sodium hydroxide neutralizes acids and was originally used a component of antacids, acting to neutralise gastric acid. The carbonate was subsequenty replaced with sodium bicarbonate, which is still part of antacid formulations such as Gaviscon.

In glass making, the addition of sodium carbonate, often referred to as a flux agent, reduces the melting point of silica (sand) and therefore the energy costs associated with glass production, which is particularly relevant today. Soda glass is predominantly used in domestic glassware, including windows. Subsequently, glassmaking has been influenced by the demand for scientific glassware, brands like Pyrex often contain boron trioxide, giving rise to borosilicates, which improve the temperature dependent expansion and contraction characteristics of glass, facilitating both cooking at home and distillation work in the laboratory.

The images on the left provide a molecular level view of the impact of soda addition to silica. The disruption caused to the symmetry of intermolecualr bonding gives rise to both spectral and chemical differences in the two forms.