Your disputes almost always arise from the want of a common agreement in the use of the words you employ, owing to the incompleteness of your language in regard to all that does not strike your senses. One fact, patent to all observers, dominates all our hypotheses. The origin and connection of these two things are unknown to us. Yes, of matter as understood by you, but not of matter considered as the universal fluid. The ethereal and subtle matter which forms this fluid is imponderable for you, and yet it is none the less the principle of your ponderable matter.
Density is a relative property.
Of one primitive element. From the modifications undergone by the elementary molecules, as the result of their union and of the action of certain conditions. This principle is proved by the fact that the qualities of bodies are not perceived by all persons in the same manner. The same thing appears agreeable to the taste of one person, and disagreeable to that of another. What appears blue to one person appears red to another.