388 DETAILED SYNTHESIS. 



only refreshingly cool, but health-giving to a remarkable degree, while 

 the same temperatures produced by the negatively electric northeast 

 winds are raw, piercing, and unsalutary ; the same is true of cellars and 

 basements, which should never be occupied for any length of time, the 

 upper rooms being the most healthy. On the other hand, air passed 

 over nearly red-hot surfaces of iron, is made negatively electric, and 

 will be wanting in ozone ; the air will be called burnt, and is very un- 

 healthy ; yet furnaces or heaters constructed so as to allow air to pass 

 over very hot surfaces, are used in many, yes, even in most educational 

 rooms. Such apparatus ought to be discarded at once, unless disease 

 is a blessing. Is it not possible to have people taught, by example as 

 well as by precept, the true office, importance, and relations of air, the 

 choicest gift of Divine Benevolence ? 



12G2. VARIOUS IMPURITIES, ARISING FROM OUT-DOOR 

 CAUSES, are found in the air at various times ; sewers, 

 marshes, etc., are such sources, while unknown causes 

 of disease often infect limited or extensive localities. 



1263. VENTILATION, OR PURITY OF AIR, HAS REFER- 

 ENCE to various things : 1st, Locality, to be selected or 

 made free from impurities ; 2d, Houses, in all their parts, 

 to be constructed so as to allow free passage of air 

 through them without exposing any one to a draft ; 

 3d, The air to be made, or preserved, positively elec- 

 tric ; 4th, Air should be kept moist, and free from dust ; 

 5th, Clothing, bedding, etc., should be often cleaned, and 

 very often aired ; 6th, The lungs themselves should be 

 often thoroughly ventilated by deep inspiration and 

 expiration. In brief, there must be thorough ventilation 

 of outdoors, indoors, and the lungs. 



1264. nius. ETHER INHALED ONE EVENING was perceived in the 

 breath the next, after active exercise ; showing that air may remain a 

 long tune hi the outskirts of the lungs during quiet breathing. 



1265. Inf. It is evidently important that THE AIR SHOULD BE VERY 

 PURE AND QUITE COOL during the quiet breathing of sleep, in order to 

 effect as thorough a ventilation as possible in the lungs, and that deep 

 expiration and inspiration should be made when a person first awakes. 



1266. Remark. There need be no fear of A COLD, or other harm, 

 BEING TAKEN DURING THE NIGHT, from cold or damp air, provided it does 



What said of air passing over ice? Red-hotiron? 1262. What said of-? 12C3. To 

 what does ? 1264. What said of ? 1265. Yhen should ? 1268. How prevent 



