Furthermore, while the attempts of the alchemists to make gold by chemical means had always met with failure, their dreams now became a theoretical impossibility.Īnniversaries provide appropriate occasions to remember significant events or personalities in the history of science. Hence Dalton’s atomic ideas immediately suggested a theory of chemical change which we still recognise today. Compounds might be decomposed back into their constituent elements, but the elementary atoms could not be destroyed or created by chemical means.
These compound atoms (as Dalton called them) had properties which differed from those of their constituent elementary atoms. Chemical reactions could now be explained by atoms combining to form aggregates.
For quantitative work, many chemists continued to use the experimentally determined equivalent weights.īut this should not blind us to the fact that Dalton’s theory set chemistry along its modern path. He produced the first table of atomic weights, but uncertainty remained about the values for many years, because of the difficulty, at the time insurmountable, of determining what we would now call molecular formulae.