Henri-Louis Duhamel du Monceau

Having been requested by the French Academy of Sciences to investigate a disease which was destroying the saffron plant in Gâtinais, he discovered the cause in a parasitical fungus which attached itself to the roots. This achievement gained him admission to the French Academy of Sciences in 1738. From then on until his death he busied himself chiefly with making experiments in plant physiology.[3]

Having learned from Sir Hans Sloane that madder possesses the property of giving colour to the bones, he fed animals successively on food mixed and unmixed with madder; and he found that their bones in general exhibited concentric strata of red and white, while the softer parts showed in the meantime signs of having been progressively extended.[3]

From a number of experiments he was led to believe himself able to explain the growth of bones, and to demonstrate a parallel between the manner of their growth and that of trees. Along with the naturalist Buffon, he made numerous experiments on the growth and strength of wood, and experimented also on the growth of the mistletoe, on layer planting, on smut in corn, and others. He was probably the first, in 1736, to distinguish clearly between the alkalis, potash and soda.[3]

From the year 1740 on he made meteorological observations, and kept records of the influence of the weather on agricultural production. For many years he was inspector-general of the marine, and applied his scientific experience to the improvement of naval construction.[3]

In his additions to l'Art de l'Épinglier (The Art of the Pin-Maker, 1761), Henri Louis Duhamel du Monceau wrote about the "division of labour":

There is nobody who is not surprised of the small price of pins; but we shall be even more surprised, when we know how many different operations, most of them very delicate, are mandatory to make a good pin. We are going to go through these operations in a few words to stimulate the curiosity to know their detail; this enumeration will supply as many articles which will make the division of this labour... The first operation is to have brass go through the drawing plate to calibrate it.

This text is believed to have inspired Adam Smith for his famous work An Inquiry into the Nature and Causes of the Wealth of Nations published in 1776.

Illustration of the Encyclopédie (vol 2b-181) article "Rope", that Duhamel wrote.

Following the work of René Antoine Ferchault de Réaumur, in 1757 Duhamel released the Descriptions des Arts et Métiers and opposed the writers of the Encyclopédie. The Encyclopédistes didn't take this well, and criticised him on occasion. For example, Denis Diderot (1767) recalled:

This Duhamel has invented an infinity of machines which serve no purpose, has written and translated a multitude of books on agriculture, of which it is not known if they have any useful result, that is still awaited.[4]

- Denis Diderot, 1767.

Diderot seems to forget his debt to Duhamel du Monceau for the Encyclopédie, including the articles "Agriculture," "Rope," "Pipe" and "Sugar."

The succession of Grandjean Fouchy, perpetual secretary of the Academy of Sciences, clash sees supporters of Condorcet, led by d'Alembert, and those of the astronomer Bailly, led by Count de Buffon. In 1773, the appointment of Condorcet as deputy Grandjean Fouchy sees the triumph of the party of the philosophers against the use of naval officers linked to Duhamel.

But in January 1775, supporters of Bailly, including Patrick D'Arcy and Jean-Charles de Borda, both naval officers make up a commission to monitor the work of the Secretary, that Condorcet considered censorship. To be elected, he must give up the pension ECU 1000 and submit an application in proper form to respect the rules of Académie2. Condorcet would later refer to this episode:

"Though he loved many innovations in science and devoted his life to introduce useful ones in the arts, he didn't like them in politics and even less in the statutes of the academies"

- Marquis de Condorcet, 1783[5]