In 1676 Newton had communicated to Leibnitz the fact that he had discovered a general method of drawing tangents, concealing the method in two sentences of transposed characters.

Sometimes Selkirk, leaving his companions in the midst of their bottles and glasses, would describe a tangent towards the counter, and come to converse with the pretty hostess.

Dr. Barrow regarded the tangent as merely the prolongation of any one of these infinitely small sides, and demonstrated the relations of these sides to the curve and its ordinates.

[Footnote 3: The deflection being measured by its tangent, it was necessary that the scale should be at right angles to the radius (the radius drawn from the mirror to one or the other end of that part of the scale which represents this tangent).

But she welcomed any tangent of nonsense that set the right key for the coincidence of their meeting.