It is to be observed touching the spirits […] That when men perceive their spirits to be in good, placid, and healthful state, (that which will be seen by the tranquility of their Mind, and chearful disposition) that they cherish them, and not change them: but when, in a turbulent and untoward state, (which will also appear by their sadness, lumpishness, and other indisposition of their mind) that then they straight overwhelm them, and alter them.
In Latin, 'amicus' belongs to the second declension. Most second-declension nouns end in '-i' in the genitive singular and '-um' in the accusative singular.
Losing this highly publicized case was an embarrassment to the firm.
Wooster: If you ask me, art is responsible for most of the trouble in the world. / Jeeves: An interesting theory, sir. Would you care to expatiate upon it? / Wooster: As a matter of fact, no, Jeeves. The thought just occurred to me, as thoughts do. / Jeeves: Very good, sir.