We had never seen anything like it and we had presence of mind to save several twigfuls of leaves, which proved to be the right food.

Jagdgeschwader 1 (JG 1), the Red Baron's Flying Circus

Now I can imagine a quaternionist (unless prejudiced) admitting the simplicity of establishment and of operation, and the convenience of the notation, and its sufficiency for practical requirements up to a certain point; and yet adding the inquiry whether there is not, over and above this vector analysis, a theory of Quaternions which is overlooked.

a nonserum protein