[I.65] as. The three forms 'that,' 'who' ('which'), and 'as' are often interchangeable in Elizabethan usage. So in [line 174]. See Abbott, §§ 112, 280.
[I.66] You hold me too hard on the bit, like a strange rider who is doubtful of his steed, and not like one who confides in his faithful horse, and so rides him with an easy rein. See [note] on l. 310.
[I.67] friend F1 | Friends F2F3.
[I.68] Caius Cassius Longinus had married Junia, a sister of Brutus. Both had lately stood for the chief prætorship of the city, and Brutus, through Cæsar's favor, had won it; though Cassius was at the same time elected one of the sixteen prætors or judges of the city. This is said to have produced a coldness between Brutus and Cassius, so that they did not speak to each other, till this extraordinary flight of patriotism brought them together.
[I.69] Merely: altogether, entirely. So in The Tempest, I, i, 59.
[I.70] passions of some difference: conflicting emotions.
[I.71] only proper to myself: belonging exclusively to myself.
[I.72] give some soil to: to a certain extent tarnish.
[I.73] behaviours. Shakespeare often uses abstract nouns in the plural. This usage is common in Carlyle. Here, however, and elsewhere in Shakespeare, as in Much Ado about Nothing, II, iii, 100, the plural 'behaviours' may be regarded as denoting the particular acts which make up what we call 'behavior.' See Clar.
[I.74] mistook. The en of the termination of the past participle of strong verbs is often dropped, and when the resulting word might be mistaken for the infinitive, the form of the past tense is frequently substituted.