Iuppiter Mercuriō imperāvit, ut omnium peccāta in testula scrīberentur, ac in arcā quādam repōnerentur, ut, singulōrum peccātīs in ūnum collectīs, iustās cuique poenās statueret. Sed cum testulae illae sint simul admixtae atque confūsae, proinde fit, ut haec cito, illa sērō in Iovis manūs incidat, sī quando ipsī eās in arcam intendere placet. Nōn itaque mīrārī dēbēmus, sī improbī hominēs celeriter quidem iniūriās inferant, tardē vērō poenās luant.
SOURCE: This comes from the Latin translation that accompanies De Furia's edition of the Greek Aesopic corpus, published in 1810 and available at GoogleBooks. This is fable 365 in De Furia; for other versions, see Perry 313.
READ OUT LOUD. Choose which marked text you prefer to practice with - macrons (above) or accent marks (below) - and read the text out loud until you feel comfortable and confident. Then, try reading the unmarked text at the very bottom. It should be easy for you after practicing with the marked texts. :-)
ACCENT MARKS. Here is the text with accent marks, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Iúppiter Mercúrio imperávit, ut ómnium peccáta in téstula scriberéntur, ac in arca quadam reponeréntur, ut, singulórum peccátis in unum colléctis, iustas cuique poenas statúeret. Sed cum téstulae illae sint simul admíxtae atque confúsae, proínde fit, ut haec cito, illa sero in Iovis manus íncidat, si quando ipsi eas in arcam inténdere placet. Non ítaque mirári debémus, si ímprobi hómines celériter quidem iniúrias ínferant, tarde vero poenas luant.
UNMARKED TEXT. Here is the unmarked text - after practicing with the marked text that you prefer, you should not have any trouble with the unmarked text:
Iuppiter
Mercurio imperavit,
ut omnium peccata
in testula scriberentur,
ac in arca quadam
reponerentur,
ut, singulorum peccatis
in unum collectis,
iustas cuique poenas statueret.
Sed cum
testulae illae sint
simul admixtae atque confusae,
proinde fit,
ut haec cito,
illa sero
in Iovis manus incidat,
si quando
ipsi
eas in arcam intendere
placet.
Non itaque mirari debemus,
si improbi homines
celeriter quidem
iniurias inferant,
tarde vero poenas luant.
IMAGE. Here is an illustration for the story (image source), showing an ancient Greek potsherd:
