Plutarch. Plutarch's Lives of the Noble Grecians and Romans
Englished by Sir Thomas North. Trans. Sir Thomas North. Vol. 6 (1579; London: David Nutt, 1896) 196.

MARCUS    in hande, but withall, dispatche I reade you, for your 
BRUTUS    enterprise is bewrayed. When he had sayd, he presentlie 
    departed from them, and left them both affrayed that their 
    conspiracie woulde out. Nowe in the meane time, there 
    came one of Brutus men post hast unto him, and tolde him 
    his wife was a dying. For Porcia being verie carefull and 
The weakenes    pensive for that which was to come, and being too weake to 
of Porcia, not-    away with so great and inward griefe of minde: she coulde 
withstanding    hardlie keepe within, but was frighted with everie litle 
her former    noyse and crie she hearde, as those that are taken and 
corage.    possest with the furie of the Bacchantes, asking every man 
    that came from the market place, what Brutus did, and still 
    sent messenger after messenger, to knowe what newes. At 
    length, Caesars comming being prolonged as you have heard, 
    Porciaes weakenesse was not able to holde out any lenger, 
    and thereuppon she sodainlie swounded, that she had no 
    leasure to goe to her chamber, but was taken in the middest 
    of her house, where her speache and sences failed her. How- 
    beit she soone came to her selfe againe, and so was layed in 
    her bedde, and tended by her women. When Brutus heard 
    these newes, it grieved him, as it is to be presupposed: yet 
    he left not of the care of his contrie and common wealth, 
    neither went home to his house for any newes he heard. 
    Nowe, it was reported that Caesar was comming in his litter: 
    for he determined not to stay in the Senate all that day 
    (bicause be was affrayed of the unluckie signes of the sacri- 
    fices) but to adjorne matters of importaunce unto the next 
    session and counsell holded, faining him selfe not to be well 
    at ease. When Caesar came out of his litter: Popilius Laena, 
    that had talked before with Brutus and Cassius, and had 
    prayed the goddes they might bring this enterprise to passe: 
    went unto Caesar, and kept him a long time with a talke. 
    Caesar gave good eare unto him. wherefore the conspirators 
    (if so they shoulde be called) not hearing what he sayd to 
    Caesar, but conjecturing by that he had tolde them a litle 
    before, that his talke was none other but the verie discoverie 
    of their conspiracie: they were affrayed everie man of them, 
    and one looking in an others face, it was easie to see that 
    they all were of a minde, that it was no tarying for them till