It must also be remembered, that when the teeth are usually produced, the milk loses its nutritious properties, and this too at a time when the infant from his increasing size must evidently require a more solid and substantial, rather than a thinner and less nourishing diet. What rational argument, therefore, can be offered why he should still be suckled? If we observe the brute creation, do any analogies appear by which we can defend the propriety in the human species of protracted suckling? by no means:--on the contrary, we find that the female animals soon drive away their young from their dugs; and what is, perhaps, still more to the purpose, I have heard stated, on good authority, as a well-known fact among the breeders of cattle, that if calves be allowed to suck beyond a few months they do not thrive, but, on the contrary, become lean and diseased. The belief so generally prevailing, that the longer a child is suckled the stronger it will become, is a prejudice, like many others concerning women and children, which has been handed down from mother to daughter for ages, and has thereby become so universally entertained and so deeply rooted in the minds of females, that even medical men scarcely venture to question its propriety. My own experience, however, compels me to declare, that there is not a more erroneous or mischievous doctrine; and I can most truly affirm, that I never yet witnessed an instance where protracted lactation had produced any good effect[D], though I have seen numerous examples (some of which will be introduced hereafter) where, I believe, it had been the indirect cause of death. Having thus strongly noticed the impropriety of long continued suckling, it will, perhaps, be proper to state my opinion as to the period when this process should terminate. As a general rule, at nine months after birth the child ought to be entirely weaned; and in no instance should he be permitted to suck more than ten. In many cases suckling may be relinquished with advantage (and occasionally it is absolutely necessary to discontinue it) before the time first above mentioned; in others, however, it may be protracted beyond it.