Here, too, he made the acquaintance of Claude Mydorge, one of the foremost mathematicians of France, and renewed an early intimacy with Malin Mersenne (q.v.), now Father Mersenne, of the order of **Minim** friars.

It is used to determine the density of a body experimentally; for if W is the weight of a body weighed in a balance in air (strictly in vacuo), and if W' is the weight required to balance when the body is suspended in water, then the upward thrust of the liquid (I) (2) "F r an **Minim** ' 'i n or weight of liquid displaced is W-W, so that the specific gravity (S.G.), defined as the ratio of the weight of a body to the weight of an equal volume of water, is W/(W-W').

The pharmacopoeial preparations of this acid are a 2% solution, which is given in doses of from two to six **minims**, the tinctura chloroformi et morphinae cornposita, which contains a half-**minim** of this solution in each ten **minims**, and the aqua laurocerasi, which owes its virtues to the presence of this acid, and is of inconstant strength, besides being superfluous.

In 1611 he joined the **Minim** Friars, and devoted himself to philosophic teaching in various convent schools.