Consequently, their language was limited. They made use of a limited number of words, or produced articulate sound enough to express just what they wanted, and no more. They may have had two or three hundred different words or sounds in use. We have men to-day among us that have not many more words at command, and their ideas generally correspond in number and quality to their stock of words. The stock of words and the stock of ideas always depend upon the amount of experience and the amount of exercise the five senses have had; together with the urgencies and difficulties they have had to contend with. The power of observation is developed in accordance as the opportunities arise. Each particular special sense develops its own faculties, from the practice, use, and experience of that sense, the role it is called upon to play as necessities arise. And as each object is perceived or observed by the special sense, it is recorded, a picture of the same is retained in the great nervous storehouse for future reference. The retention and recognition of the same goes to the formation of memory. As the stock of objects increases, words or sounds designating the same also increase in number, and the material for the formation of ideas is also largely increased. Ideas can be formed only about such things as we know, or rather such things as any one special sense has been impressed with, has perceived and recognized. Those things or beings by which any one sense has not been impressed, the mind neither has perceived nor is able to recognize. Everyone, whether barbarian or civilized, is perfectly familiar with those things or beings that immediately surround him--that is, all those things and beings which the senses have already been impressed with, perceived and recognized. Sounds, or words, have been invented to designate all such; and these are known; the picture representing any one object is retained, stored away in the great nervous storehouse, the brain--are remembered. The oftener a thing is perceived, the more familiar it becomes and the more easily recognized, the firmer it becomes fixed and the more easily it is recollected. Thus primitive man, with his few wants, and these wants amply supplied by nature, had or invented names for all of them. These formed the earliest collection of names of objects--their appearance, their actions, their habits, etc. All these qualities were associated, identified, and presented by words, in due time, without the presence of the objects. That is to say, the simplest ideas were in this manner formed, and the ideas so formed corresponded with the number of words, and the number of words corresponded with the number of impressions received by the senses.