By powerful boiling at a strong fire without smoke, the serous part of the milk is separated from the caseous, and is then strained through a sieve or piece of rag carefully, and to the serous part is added a moderate quantity of honey, or of vinegar and honey, or salts; and it is given to evacuate the bowels in the quantity of two sextarii to adults, and to younger persons not less than a sextarius. And milk thickened by ignited pebbles or iron may be given with advantage for dysenteries and alvine discharges. * * * * * COMMENTARY. The method of preparing the schiston is thus described by Pliny: “Medici speciem unam addidere lactis generibus, quod schiston appellavere. Id fit hoc modo: fictili novo fervet caprinum maxime, ramisque ficulneis recentibus miscetur, additis totidem cyathis mulsi, quot sint heminæ lactis. Cum fervet, ne circumfundatur, præstat cyathus argenteus cum frigida aqua demissus ita ne quid infundat: ablatum deinde igni refrigeratione dividitur et discedit serum a lacte.” (Hist. Nat. xxviii, 33.) The same process is briefly described by Dioscorides (ii, 77.) Pliny recommends the whey thus prepared for epilepsy, melancholy, paralysis, leprosy, elephantiasis, and arthritis. This preparation of milk is often noticed by the ancient authors on medicine. It evidently consisted of the whey of the milk, separated from the cheese by a peculiar process. The melca was a preparation from milk, and is mentioned by our author in the Fourth Book § 27. It also appears to have been a sort of curds and whey, or _du lait caillé_ of the French, prepared by pouring hot vinegar upon milk. The process is minutely described in the Geoponics (xviii.) The oxygal, or lac acidum, consisted of the caseous part of the milk, separated from the whey by a very complicated process, which is fully described by Columella. (xii, 8.) It is said by Galen to possess very refrigerant properties. The aphrogala, or spuma lactis, appears to have been milk reduced to a state of foam by violent agitation. SECT. LXXXIX.—ON CHEESE. All cheese is acrid, occasions thirst, is difficult to digest, forms bad chyme, and engenders stones. That is best which is new, spongy, soft, sweet, and has a moderate share of salt. The opposite kind is the worst. * * * * *