xxxiv Appendix. 
by sympathy with the like states in those among whom the child receives 
his early education. It is of the utmost importance, therefore, that the 
companions of young children should be such as it is wholesome for them 
to imitate; since it is upon the habits of feeling thus early formed that the 
happiness and right conduct of after-life mainly depend. We must carefully 
watch and understand the disposition of our children, so as to suit their 
surroundings to their peculiar wants. - To allow a child who is perhaps dull, 
and of what is known as a phlegmatic nature, to associate constantly with 
another child similarly constituted, or with one who is in any way deficient 
in mental power, would be to risk the healthier child, and probably cause 
him to grow up dull and sullen; our object should be to choose companions 
for him quick and bright, and with as much animal life in them as possible, 
so that the heavier child may from association catch some of their brighter 
ways, and gradually grow into more cheerful thoughts and habits. It may 
perhaps be urged in answer to this statement, that, as a general rule, the 
activity with which the formation of new ideas takes place in a child, and 
the quickness with which the attention transfers itself from one object to 
another, prevents any single state from fixing itself, in anything like a per- 
manent manner, in the mind, so that memory preserves but faint traces of 
the greater part of what passes through the mind; this is undoubtedly true, 
but it must be remembered, that although individual impressions are more 
speedily dissipated from the minds of children, than from those of adults, 
yet that when impressions of the same kind are frequently repeated, the 
` brain grows into them in such a way that they become part of it, and take 
part in its ordinary working ; and thus by establishing a particular mode of 
nutritive assimilation, they tend to perpetuate this acquired habit, of what- 
ever nature it be. As there is constant change going on in the body, old 
particles giving place to new ones, and these again to others, it may be 
thought that the diseased particles would in time die out, and give place to 
new healthy ones. This is not the case, for each atom of the body imparts 
to the atom that takes its place its own structure in every way, so that 
marks, as scars and moles, never die out, but last as long as the person 
possessing them lives. 
A writer on diseases of childhood says, ** Looking at the physical health 
of a child, as a means of judging of its mental strength, I think the com- 
mencement of the second dentition is the earliest period when instruction 
requiring brain-work can be safely pushed. Even then the knowledge 
should be of a kind which accords with the evolution of the different 
faculties, or the mind will become disgusted with the difficulties placed 
before it, and not having mastered simple subjects it will be unfit to receive 
more complex ones ; hence, precise methods of instruction, and exact defi- 
