It has been a common practice to give Magnesia to children as a preventive, and to mix it for this purpose with their food, in order to correct that disposition which milk and the farinaceous aliments have to turn sour. This however should be done with caution, for it is only the excess of acidity which is prejudicial to infants,[l] some degree of it is necessary; and should we too officiously and entirely destroy, what we ought only to restrain within due bounds, we may create disorders of an opposite nature to those we have endeavoured to prevent, and instead of an acid, produce an alkalescent disposition in the first passages. Indeed I fear that diseases have been more frequently created than obviated by the use of preventive medicines, and they should only be allowed in cases where the approach to disease is manifest. But when a child is in a healthy state, the best means to preserve him from a superabundant acidity, is to pay due attention to the regulation of his diet, to give him proper exercise, not to confine him too much in the foul air of hot unventilated rooms, to wash his whole body every day in cold water, and to rub him very well night and morning with a dry flannel, taking care that his stomach be not too full at the time when this friction is performed. [l] Hactenus monstravimus, sicut cordis, musculorumque vires debiles erant, ita et solidorum quoque statum necessario imbecillem fuisse, et succos tenues, dilutosque; ut natura ampliationem vasculorum facilius efficeret, et incrementum animale minori cum molestiâ perageret. Sed ne status iste tonusque partium debilis laxusque ultra modum procederet (quod sæpe accidit, morbosque excitare solet) acidum quoddam juvenilium animalium stomachis datum est, quod quamvis aluminis instar, lac coagulat, atque ob eam causam aliquando morbum procreat, tamen fibrarum tonum astringet confirmatque, et putredinem omnem alkalinam, a qua alioquin periculum esset, reprimit. Quod quidem videri est, vel in coagulo stomachi vitulini, vel in aliis animalibus: sed istud tamen acidum, quod infantibus tarn idoneum est, redundat fortasse nonnumquam, et vel per testaceas pulveres, vel per medicamenta antiacida, ut supra dixi, corrigi debet. Russelli OEconomia Naturæ, p. 56. Nor would I advise parents to rely with too much security on the virtues of this medicine, where the disorders of their children are complicated, or obstinate. The advice of the sagacious and distinguishing practitioner will then be necessary to direct what method of treatment is to be pursued. Nor can I here avoid lamenting that the management of children when diseased, is so often in the hands of nurses and ignorant women, from an absurd notion that their diseases are not proper subjects of medical investigation; when in truth, there are none which require a clearer judgement, a quicker penetration, or a greater share of medical knowledge in the prescriber.