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< HKMISTRY. 





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Miial, drinking water u positively to bo rwcom- 



Beer and wine at dinner are also hurtful only if taken 



:n the Utter case, the alcohol coagulate* 



the all.uniiii.'iu substances not only of the food, but 



also of the digestive fluids, anil thus disturbs digestion. 



If taken in a moderate quantity, such beverages are 



calculated to cause the meal to hold out longer; for the 



fact that we are not so soon hungry again after taking a 



meal with wine, than if we have taken only water with it, 



U to be accounted for by the slower combustion of the 



H of our body, because the alcohol we have 



cd, takes possession of the inhaled oxygen. Hence, 



with a meal is extremely useful when a long 

 journey, or work in hand, renders it impossible to 



food again at the usual time ; so much the more 

 so, as such detention from food itself usually causes an 

 acceleration of the metamorphosis of the tissues, which 

 beer and wine efficiently obviate. 



The general preference of warm food at dinner is 

 based on rational grounds; for a low temperature co- 

 agulates gelatine, and the fata coagulate, which are much 

 more readily digested in a liquid state. But when the 

 food is much cooler than the liquids of the stomach and 

 intestines that is to say, much lower than 08 Fah. it 

 subtracts from the hitter a part of their warmth, and 

 tke colder combination effects the solution less readily. 

 Ice, therefore, as well as very cold water, are injurious, 

 particularly if the nutriments contain a large proportion 

 <>f fat or gelatine. As great changes of temperature in 

 our body in general ore not easily endured, a sudden 

 transition from warm food to cold, or vice vena, is 

 injurious. By the sudden refrigeration of the heated 

 cavity of the mouth, the enamel of the teeth is said 

 sometimes to have actually cracked. 



From tho different hour at which the principal meal 

 is taken by different individuals and classes, it suiti- 



v follows tliat no absolute rule can be given for 

 it This time is of little consequence to the classes 

 having an occupation chiefly mental, and of none to 

 those who do not work at all, provided, at least, they do 

 not so utterly subvert the natural order of life, that night 

 becomes day, and day night. Those classes, however, 

 which are engaged in fatiguing,' bodily exercise, expend, 

 during the first six hours of the day, so great a quantity 

 of material, that almost everywhere they observe the 

 custom of taking at noon, or at least not much later, 

 their largest portion of restoratives. 



5 92. Happen. Tho German custom of taking supper 

 two or three hours, or even longer, before going to bed, 

 has this great advantage that digestion is almost at 

 an end before going to sleep ; for digestion disturbs 

 sleep, and sleep digestion. Hence, supper should con- 

 sist, as much as possible, of easily digestible aliments, 

 as soups, salad with little meat, and not of fish or legu- 

 minous seeds. It is only when supper is taken very 

 early, that the less digestible bread, or, still better, 

 bread-and-butter, and meat, are proper food. When 

 tea is taken in addition, those who are accustomed to 

 perform close mental labour after supper, are agreeably 

 excited. Intemperance is, most of all, to be avoided in 

 the evening ; for, apart from the sleep being disturbed 

 by digestion as well as by hunger, an overloaded state 

 of tho blood is less easily adjusted during the night. 

 In the night, less carbonic acid is exhaled, and the 

 tuHue-chaugo in general retracted. Hence, an overladen 

 state of the tissues, and especially of the brain, is very 

 often manifested in the night by heavy dreams and night- 

 mare, and in tho morning by headache and a general 

 state of ill-humour. 



93. Diet of Childhood. In the form of a general 

 proposition, and with application to special cases, wo 

 Lave repeatedly insisted upon the pnnciplc, that the 

 amount of restoratives needed by the system, depends 

 upon the extent of the expenditure. An abundant 

 supply, accompanied by considerable expenditure, occa- 

 sion* an active metamorphosis of tissues. 

 Although the differences in human beings, as modi- 



fied by ago and sex, generally confirm this proposition, 

 so that in a healthy man the activity of tho tissue-change 

 may bo estimated by tho quantity of tho outgoings, 

 still it is precisely here that wo find, at the first glance, 

 the most important exceptions. I u tho adult, the weight 

 of tho whole body remains from day to day the same, 

 allowance being made for the augmentation or diminu- 

 tion most recently produced either on the one hand l>y 

 a meal, or on the other by excretions of different kinds ; 

 for here, in general, the restoratives exactly repair the 

 loss of the excretitious parts. 



Not go with tho child : for that tho infant grows to a 

 boy, the boy to a youth, is entirely anil solely effected 

 by tho receipt surpassing the expenditure. Tho balance 

 is not oven in the exchange of the body. \V. h.r.c not 

 to deal with a simple tissue-change. Growth consists 

 in nothing else but in the proportion in which the for- 

 mation of tissue exceeds the products of regressive trans- 

 formation. The superior activity, however, of nutrition 

 over excretion is the cause only of growth. The assi- 

 milation of the body in a greater proportion than it 

 expends, is the condition without wlu'ch it cannot grow. 

 Strictly speaking, this greater appropriation of alimen- 

 tary principles is growth itself. But its cause has to be 

 more profoundly sought. Tho blood and the tissues of 

 the infant are of a different composition from tin 

 tho adult. When treating of animal food, we mentioned 

 that the muscles of young animals contain a greater pro- 

 portion of albumen, but less of fibrino, than those of 

 the full-grown. The real skin, in the adult consisting of 

 fibres yielding gelatine, is formed in the infant from an 

 albuminous substance, which, however, is not entirely 

 absent from the skin of the adult. The bones of tho 

 infant yield gelatine of cartilages or " chondrogen ;" 

 and the organic basis is by degrees only changed into t ho 

 tissue yielding gelatine of bones, or " collagen." Thus, 

 while in youth, the solid parts contain a greater propor- 

 tion of water, but less in weight of tho formative sub- 

 stance deposited by the mother-juice ; tho tissues of the 

 adult are, on the contrary, remarkable for their abun- 

 dance of solid substance. As these solid substances are 

 mostly heavier than water, .their augmentation during 

 the period of growth, explains the increase of the body 

 in weight. 



But if the body of the child have another composition 

 than that of the youth, v. , must not be satisfied with tho 

 fact that the quantity by which tho receipts surpass the 

 expenditure, effects the growth. Tissues of a different 

 composition likewise possess a different kind of attraction 

 for the matters conveying the nutriment to tho blood. 



Tho muscles of the child attract fibrine from the blood, 

 and their albuminous substances decompose into kreatine 

 and urea ; and tho important consequence of their com- 

 position differing from the muscles of the adult is, th:it 

 tho fibrino attracted, surpasess in quantity the products 

 of decomposition taken from them by tho retransfor- 

 mative process. The same change takes place with tho 

 skin, as its albuminous substance is decomposed and lost 

 with the urine and the exhaled air ; while, with a superior 

 attractive power, it forms from the blood, and assimilate! 

 tho organic matter of its gelatinous fibres. But tho 

 n mark is chielly applicable to the bones; for just as 

 those, more tliau any other tissue, cause the inciv:. 

 weight of tho whole body, so do they attract, in return 

 for the wasting matter (known by yielding, when boiled, 

 gelatine of cartilage instead of bone-gelatine), such an 

 abundance of tho true bone-constituents, that in a very 

 short time their composition entirely changes. While 

 gelatine of cartilage possesses a strong alii nity for com- 

 mon salt, the tissue yielding bone-gelatine has the 

 greatest tendency to combine with the phosphate and 

 carbonate of lime. With the growing preponderance, 

 therefore, of the bone-gelatine over the gelatine of 

 cartilage, tho lime-salts are continually increasing, and 

 that during tho whole life. The bones readily collect 

 the lime-salts and tho fluoride of caleium from the blood, 

 .1 function shared in equal degree by the teeth only. 



This strong attractive power, peculiar to tho infant 

 and child, is more than the condition it is tho real 



