A False Sense of Simplicity

According to the London doctrine, a small amount of carbonic acid in water prompted the formation of an insoluble carbonate of lead on the interior of the pipes. In this way, the London doctrine stated the exact opposite of other variants of the doctrine of protective power. Weak and colorless, carbonic acid is formed by the dissolution of carbon dioxide in water. Adams argued that several prominent chemists in London used this doctrine to justify the proposition that London could have continued to use lead service pipes safely if the city switched to a soft, and more corrosive, water supply. At the time Adams was writing, London drew its water from the river Thames, a hard-water source. Evidence to follow, however, raises serious questions about the London doctrine. 

Adams was not the only observer to suggest caution in trying to predict the solvency of particular water supplies. Even proponents of the doctrine of protective power published articles encouraging doctors to be sensitive to the possibility of water-related lead poisoning among individuals who drew their water from supplies pronounced safe by prominent chemists. For example, in 1860, James R. Nichols published an article in the Boston Medical and Surgical Journal arguing that water supplies in Massachusetts were usually safe because they contained 

Several examples illustrate the unpredictability of the lead solvency of any given water supply. First, during the 1880s, cities and towns in the north of England experienced a severe outbreak of water-related lead poisoning. The British Medical Journal estimated that as many as eight million people might have been affected by the epidemic. The specific 

It will be seen that the presence of sulphuric acid, even in very small quantity, notably increases the tendency of the water to act on lead. Repetition of the experiments always furnishes results pointing in the same direction, but the acmal figures vary from time to time, being probably influenced by variations in the composition of the water. 

Many other writers of the time also believed that coal-burning factories and homes played an important role in the propagation of water-related lead poisoning.  

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