324 Chronicles of Science. [-A^pril, 



or nearly fresh-water of Victoria Docks is not without parallel. 

 It is an important subject for inquu-y, as to how the fauna of the 

 Victoria Docks originated. Is it the representative of an ancient 

 marsh fauna, presenting in its Nudibranch and Hydrozoon an indi- 

 cation of the recession of the sea ? Or has Embletonia been intro- 

 duced with ships and established itself, and has Cordylo^yhora, long 

 since adapted to lacustrine conditions, also been introduced since the 

 time when the area was a marine one ? 



Physiology. 



Influence of Section of the Fneumogastric Nerves on 

 Resjnratioji. — Herr Voit, of Munich (a physiologist, whose writings 

 on the subject of the connection between muscle-oxidation, food, and 

 muscular work, as opposed to Liebig's old teaching, were of much 

 value, and of early date in the late revulsion of scientific o2:>inion on 

 that subject), has experimented on the effect of cutting the pneumo- 

 gastrics as to respiration. Previous experimenters have shown that 

 the amount of carbonic acid exhaled after section of the nerve, is 

 the same as that before. The author and Dr. Eaber find now 

 that this is true only for the first few hours after the operation. 

 At a later period when the tissue of the lung has begun to undergo 

 a change, the quantity of carbonic acid diminishes rapidly, and that 

 of oxygen is increased. 



Influence of Bespiration on the Temjperature of the Blood. — • 

 Dr. Lambard, of whose wonderfully delicate thermo-electric appa- 

 ratus we sj)oke in our last Chronicle in relation to the temperature of 

 the head, capable as it is of indicating a difference of temperature 

 of about TrT,'o-f.th of a degree centigrade, has been ajjplying his instru- 

 ment to the study of the efiects of respiration on the temperature 

 of the blood. One apparently anomalous result which he obtained 

 is this — though the air taken into the lungs, and consequently into 

 the blood, be quite cold and dry, it does not lower the temperature 

 of the blood sufiiciently to be appreciable by this delicate thermo- 

 meter, as compared with the temperature when the air respired 

 is hot. We must all of us have noted the feeling of heat in the 

 lungs on a cold frosty day —a sensation which is not experienced in 

 warmer weather, and which is the very reverse of what we should 

 expect from the greater coldness of the inspired air. ]\1. Brown- 

 Sequard suggests that the explanation may be this— the lower the 

 temperature of the inhaled oxygen the greater will be the amount 

 absorbed according to a well-known law in physics, and hence 

 possibly, there being a larger absorption of oxygen, there may be 

 increased oxidation, and increased heat accordingly. The tension of 

 the vessels aftected by cold air, may have some connection with the 

 sensation in the lungs. 



