THE UNIVERSAL FAMILY PAPER FOR INTER-COMMUNICATIONS ON 



NATURAL HISTORY-POPULAR SCIENCE-THINGS IN GENERAL. 



Conducted by WILLIAM KIDD, of Hammersmith,— 



Author of the Familiar and Popular Essays on "Natural History;" "British Song 

 Birds; " "Birds of Passage;" "Instinct and Reason;" "The Aviary," &c. 



"the OBJECT of our work is to make men WISER, without obliging them to turn over folios and 



QUARTOS. — TO FURNISH MATTER FOR THINKING AS WELL AS READING." — EVELYN. 



No. 47.— 1852. 



SATURDAY, NOVEMBER 20. 



Price 3d. 



Or, in Monthly Parts, Price Is. Id. 



AIR AND ATMOSPHERE. 



WE HAVE RECEIVED A COPY OF A VERY 



excellent book for "review;" and we 

 imagine we cannot do better than permit it 

 to speak for itself.* It wants no recom- 

 mendation from us, beyond the announce- 

 ment of its existence. It will soon make its 

 own way. The article we have selected from 

 many hundred others, equally interesting, 

 refers to what we are so often harping upon 

 — the necessity for understanding the nature 

 and value of air and atmosphere. 



Themr in which we live and breathe (says 

 the writer), consists simply of a mechanical 

 mixture of the two gases, oxygen and nitro- 

 gen, in the proportion of twenty-three parts 

 of the former to seventy-seven parts of the 

 latter — by weight — in every hundred. The 

 atmosphere not only consists of this air, but 

 also includes various other substances ; of 

 these, the principal are watery vapor and 

 carbonic acid ; ammonia and nitric acid exist 

 in minute proportions, and exhalations of 

 various kinds and amount, according to 

 situation and circumstance. 



The weight of our atmosphere, amounting 

 to fifteen pounds upon every square inch of 

 surface exposed to it at ordinary levels, 

 exerts a pressure of nearly fourteen tons dis- 

 tributed over the surface of every grown 

 man ; we do not feel this, because it is 

 counteracted by the aeriform elasticity of 

 the fluids contained within our bodies : but 

 when the pressure of the atmosphere is taken 

 off any portion of the surface, as by an 

 exhausted cupping-glass, it is the elastic 

 counteracting force within the body which 

 pushes up the covered portion of the skin. 

 The prime, essential constituent of the at- 

 mosphere, is oxygen — the sustainer of animal 

 life ; its dilution with four parts of nitrogen, 



* The Dictionary of Domestic Medicine and 

 Household Surgery. By Spencer Thomson, M.D., 

 L.R.C.S., Edinburgh and London: Groombriclge 

 and Sons. 



exactly adapts it to our requirements. The 

 proportions of oxygen and nitrogen in the 

 atmosphere do not vary ; its quality is 

 chiefly altered by the amount of watery 

 vapor, carbonic acid and other gases, and 

 exhalations, and by the rarefying or con- 

 densing effects of heat or cold. The im- 

 portance to health of a due supply of pure 

 air, and the knowledge of the principal 

 sources of its vitiation, are becoming every 

 day better understood and acted upon. 



The most constant and extensive source 

 of impurity is animal respiration. Every 

 breathing animal, man included, is continually 

 drawing into the lungs air, and the next 

 moment giving out, instead of the life-sus- 

 taining oxygen, poisonous carbonic acid. It 

 is evident from this, that if an individual orin- 

 dividuals are enclosed in a room which pos- 

 sesses no means of ventilation — in other words, 

 which has not its air continually changed, 

 the -air contained in that space must become 

 unfit to be breathed ; health will suffer, life 

 may be extinguished. The head-aches and 

 uneasy sensations caused by close crowded 

 rooms, are familiar to all ; the tragedy of the 

 Black Hole of Calcutta, and that of the Irish 

 steamer a few summers ago, are notorious. 

 In the latter, sixty persons fastened down in 

 a close small cabin, perished in less than six 

 hours. These individuals were actually 

 poisoned by the carbonic acid gas they had 

 themselves expired. 



Such effects are too obvious to require 

 comment ; it is the gradual undermining of 

 health, the slow poisoning of those who 

 habitually breathe a vitiated air, to which 

 attention requires to be drawn ; and more 

 particularly in the case of sleeping apart- 

 ments. When it is considered that one per 

 cent, of carbonic acid in the air will cause 

 uneasiness, that ten per cent, is the probable 

 limit where immediate danger to life com- 

 mences, and that every adult man vitiates at 

 least two hundred and sixteen cubic feet per 

 hour of the pure element — it is needless to say 

 more upon the necessity for proper venti- 



VOL. II. 



