Nitre, vitriol, cinnabar, alum, salt ammoniac, sublimated mercury, rock salt, alcali salt, common salt, rock alum, alum schist, arsenic, sublimate, r… - Leonardo da Vinci

Avoid the precepts of those thinkers whose reasoning is not confirmed by experience.

It is true that impatience, the mother of stupidity, praises brevity, as if such persons had not life long enough to serve them to acquire a complete knowledge of one single subject, such as the human body; and then they want to comprehend the mind of God in which the universe is included, weighing it minutely and mincing it into infinite parts, as if they had to dissect it!

Las ostras se abren por completo cuando hay Luna llena; y cuando los cangrejos ven una ostra abierta, tiran dentro de ella una piedrita o un trozo de alga, a fin de que la ostra no pueda volver a cerrarse y el cangrejo pueda devorarla. Este es también el destino de quien abre demasiado la boca, con lo cual se pone a merced del que lo escucha.