Joule afterwards proved (see below) that Mayer's assumption was in accordance with fact, so that his method was a sound one as far as experiment was concerned; and it was only on account of the values of the specific heats of air at constant pressure and at constant volume employed by him being very inexact that the value of the mechanical equivalent of heat obtained by Mayer was very far from the truth.
In early inquiries a great point was made of the prevention of putrefaction, and work was done in the way of finding how much of an agent must be added to a given solution, in order that the bacteria accidentally present might not develop. But for various reasons this was an inexact method, and to-day an antiseptic is judged by its effects on pure cultures of definite pathogenic microbes, and on their vegetative and spore forms. Their standardization has been effected in many instances, and a water solution of carbolic acid of a certain fixed 'strength is now taken as the standard with which other antiseptics are compared.
With this use of the word, philologically inexact, but historically quite defensible, may be compared the use of the word English, which is not exactly the language of the Angles, or of the word French, which is not exactly the language of the Franks.
His chronology is, for a contemporary, inexact; and he occasionally inserts duplicate versions of the same incident in different places.
It is therefore inexact to count him among the regicides, as was done by the royalists after 1815.