252 REVIEWS — HUMAN PHYSIOLOGY. 



as in lifting for instance, does not produce the same effect even 

 though the vessels swell and be visibly prominent. 



To the portion of the extract which we have sketched and amplified we 

 said that we offered no objection, but to that portion which we have itali- 

 cised we do make exception. We cannot perceive why and how different 

 bronchial trees (an expression equivalent to ramification we suppose) 

 come into action at different periods of time, some contracting (we omit 

 the word being as redundant and in reality ungrammatical), while others 

 are dilating. Most assuredly nothing proves this ; in the normal state 

 the air penetrates to the utmost bounds of the ramifications, but with 

 unequal velocity, yet, in equivalent regional zones, if we may so geo- 

 graphically designate them, in equal quantity, in a proportion best 

 perhaps expressed by the inverse ratio of the distance from the glottis, 

 every vesicle dilating and contracting synchronously, all receive the 

 purified air simultaneously, all partially expelling the vitiated air 

 coincidentiy ; the first portions of this air, when tested, giving a 

 notably smaller percentage of carbonic acid than the last portions. 

 We cannot conceive that some air cells are patent to receive, while 

 others in their vicinity are contracted to expel air ; were this so, what 

 oscillation, so to speak, would ensue ? Just such as we have revealed 

 in some forms of asthma and emphysema, and even occasionally in 

 bronchitis, and the first period of tuberculosis : certainly not the soft, 

 breezily audible whisper or murmur which the ear detects and experi- 

 ence regards as the manifestation of the normal of healthy breathing ; 

 and so too is audible the same sound, but shorter in duration, during 

 expiration, and this, without disease, as Cammann's stethoscope 

 proves. The third stage or the passage of the oxygen from the air 

 cells to the blood is carefully explained, and the volume of the oxygen 

 absorbed being greater than that of the carbonic acid evolved is shown 

 not to depend on the diffusion law of volumes of these gases as origi- 

 nally given by Professor Graham, and adopted by Valentin and Brun- 

 ner, but on the conjoint condensing action of moist membranes, as of 

 the cell wall, of the pulmonary capillary vessel and of the blood disc, 

 which action disturbs the condition of ordinary diffusion. For these 

 views, partly the result of his own experiments and of those of Pro- 

 fessor Mitchell of Philadelphia, we refer the reader to the work itself. 



This, by the way, would seem to indicate that the author regards 

 the blood disc as an oxygen carrier, so indeed he says, p. 128 : 

 "They (the discs or cells) receive that vivifying principle as they move 

 over the respiratory cells, and freighted with it, pass to all parts of 

 the body, not united with it, nor disorganized, nor burnt up by it, but 



