300 LITERARY AND SCIENTIFIC. 



throw off carbonic acid), the oxygen is absorbed, and carbonic acid given off in its 

 stead, and so different are the qualities of the two gases, that the former communicates 

 greater brilliancy to charcoal burnt in a vessel which contains it, and has in many 

 instances been inhaled with considerable benefit in diseases of the lungs ; the latter 

 is unable to maintain life, and a lighted taper is immediately extinguished if placed 

 in it — hence arises the practice of putting a lighted candle down wells, and in 

 places that have long remained unopened, before any person descends into, or 

 enters them, a practice founded on correct principles, for no gas that will not 

 maintain flame can support human life. Carbonic acid gas is also given off from 

 the lungs at each expiration, and the oxygen which is absorbed in its stead, having 

 combined with the blood, passes into the circulation ; and whatever tends to 

 increase the consumption of the latter gas, must act prejudicially on the human 

 system. Curtains drawn closely round a bed, by excluding the external air, and 

 small, ill ventilated apartments, thus become injurious." 



Before taking leave of this subject, we cannot refrain from observing 

 that all Literary and Scientific Institutions would do well to weed the 

 lectures, as much as can be done so consistently, from the dry tech- 

 nicalities of science, having always found that the knowledge imparted 

 through the medium of the fancy and affections, becomes more firmly 

 rooted in the memory than that which is inculcated by the abstruseness 

 of science and the dogmatism of learning. We are now speaking, be it 

 observed, on the part of the rma;ec? assemblies, in which many ladies con- 

 gregate, and many gentlemen, too, be it known, purely for the purpose 

 of receiving knowledge through the channel of amusement. The learned 

 cynic may say — '* what do such persons want at scientific and literary 

 meetings ?" We will answer that question — they seek for instruction 

 and amusement blended. If the former be gradually and pleasurably 

 imparted to them, they will soon disdain to have recourse entirely to the 

 latter, and we shall then see if the love of science and of general know- 

 ledge do not spread more ardently and universally than it does even at 

 the present time. Verbum sat. 



PNEUMATIC CHEMISTRY. 



The lecture on Monday, the 13th of October, was delivered by Mr. 

 Reece, at the Athenaeum : — the subject — Pneumatic Chemistry. 



The lecturer commenced by drawing a line of distinction between Pneumatic 

 Chemistry and that branch of Natural Philosophy called Pneumatics: the former 

 having for its object the consideration of the chemical composition of our atmosphere, 

 the exhibition of its elementary constituents, and the analysis and investigation of 

 all permanently elastic fluids; and the latter the mechanical properties of the 

 atmosphere, as its compressibility, elasticity, gravity, and inertia. He proceeded 

 by enlarging on the great importance of the atmosphere for the existence of both 

 animal and vegetable life, and the changes that are effected in it, by the appropriation 

 of a certain portion which is found adapted to their systems. Man, he observed, has 

 been looked upon as a perfect model of mechanical structure, and the anatomy 

 of his frame was the early guide to the study of mechanics. The chemist looks on 

 the system of man as a chemical laboratory, where nature is performing her silent 

 but not less effectual changes ; the pneumatic chemist, as illustrative of a perfect 

 pneumatic apparatus, possessing the power of rarifying and condensing, decom- 

 posing and recomposing the agreal fluids. Mr, R, then explained in a clear and 

 comprehensive manner the important function of respiration, which, he observed, 

 was divided by physiologists into two distinct operations — inspiration, or the act of 

 drawing air into the lungs — expiration, the act of expelling it from them, which 

 commence the moment we are born, and continue as long as we live ; they are 

 partly voluntary and partly involuntary, continuing during sleep and apoplexy, when 

 the will has no power ; but, on the other hand, we are able to increase, diminish, 

 accelerate, or retard these operations as we please— and though food is essentially 



