§140. Prices of Slaves.--The prices of slaves varied as did the prices of other commodities. Much depended upon the times, the supply and demand, the characteristics and accomplishments of the particular slave, and the requirements of the purchaser. Captives bought upon the battlefield rarely brought more than nominal prices, because the sale was in a measure forced (§134), and because the dealer was sure to lose a large part of his purchase on the long march home through disease, fatigue, and especially suicide. There is a famous piece of statuary representing a hopeless Gaul killing his wife and then himself (Fig. 30). We are told that Lucullus once sold slaves in his camp at an average price of eighty cents each. In Rome male slaves varied in value from $100, paid for common laborers in the time of Horace, to $28,000 paid by Marcus Scaurus for an accomplished grammarian. Handsome boys, well trained and educated, sold for as much as $4,000. Very high prices were also paid for handsome and accomplished girls. The music girls in Plautus and Terence cost their lovers from $500 to $700, but girls of the lowest class sold for as little as $25. It seems strange to us that slaves were matched in size and color as carefully as horses are now, and that a well-matched pair of boys would bring a much larger sum when sold together than when sold separately. §141. Public and Private Slaves.--Slaves were called _servī pūblicī_ and _servī prīvātī_ according as they were owned by the state or by individuals. The condition of the former was considered the more desirable: they were not so likely to be sold, were not worked so hard, and were not exposed to the whims of a capricious master. They were employed to take care of the public buildings and as servants of the magistrates and priests. The quaestors and aediles had great numbers of them in their service, and they were drilled as a corps of firemen to serve at night under the _triumvirī nocturnī_. Others were employed as lictors, jailers, executioners, etc. The number of public slaves while considerable in itself was inconsiderable as compared with that of those in private service. §142. Private Slaves.--Private slaves either were employed in the personal service of their master and his family or were kept for gain. The former, known as the _familia urbāna_, will be described later. The latter may be classified according as they were kept for hire or employed in the business enterprises of their master. Of these last the most important as well as the oldest (§129) class was that of the farm laborers (_familia rūstica_). Of the others, engaged in all sorts of industries, it may be remarked that it was considered more honorable for a master to employ his slaves in enterprises of his own than to hire them out to others. At the same time slaves could always be hired for any desired purpose in Rome or any other city.