Sulphur autem aliud est viuum scilicet. quale est, quando de terra est eductum. Aliud est mortuum vel extinctum, scilicet quod solet fieri artificiose, scilicet quod in calamos funditur vel in alia vasa. Eligendum autem est pro medicina uiuum, colore et resplendens, perlucidum, et fine lapide album vel veride, quod missum in ignem, colorem facit vitidem atque pinguem.  Virtutem habet dissoluendi, consumendi, attrahendi, subtilandi, attenuandi, reformandi vel recuperandi. Et ideo tussim prohibet, epilepticos iuuat, scabiem purgat, venenis obuiat, lethargicos excitat, arteticos, podagricos, paralyticos iuuat, si modo debito medicinaliter ipsius remedio quis utatur, ut dicit Auicenna et Dioscor, et Plato et alii autores.

Uses of the Ablative
The original use of the ablative case was to express the idea of separation, and these separative uses survive in Latin in the following forms:

• ablatives of separation
• ablative of comparison
• ablative of cause

The relationship among them may become clearer if you think of comparison as starting at a point of comparison and moving away from it (in the direction of being taller, smarter, earlier, etc.), and of events as arising from a cause. These uses will frequently require a preposition like ab, ex, or de.

In addition to its separative uses, the ablative can have an instrumental sense, which can express ideas like:

• the instrument used to do something
• the manner in which something is done
• the degree of difference (“he was taller than me by five inches”)
• with adjectives, the quality of something (also called the descriptive ablative)
• the price of something
• the ablative absolute
• ablative with special deponents like utor, fruor, fungor, vescor, etc.

These uses will not usually call for a preposition, though you will sometimes find cum used with ablatives of manner.

Put the nouns indicated below into the ablative, and identify the ablatives as separative or instrumental.

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