ON THE ALKALINE METALLOIDS. 359 



different parts of the opercula are furnished. The osphrom 

 menes goram^/y the organization of which has been described 

 and figured from Commerson by de Lac^pcde, and which 

 appears to possess the same organ, as far as may be judged 

 from the strucfure and analogy. The macropteronotus 

 sharmuth, the supplementary bronchia; of which have been 

 described by prof. GeoffroyiiB. the 3rd Tolume of the Bul- 

 letin des Sciences. The tetrodon Honkenii^ figured by 

 Bloch under the name of herisson tigre^ which has exhi- 

 bited the same organs to Mr. Schneider. And lastly the 

 hydrargyrus swampine Lac, which Mr. Bosc found in 

 Carolina, and of which he has given us some specimens for 

 the Museum. In this fish I have just found these organs. 



From the preceding facts it appears to follow, that the Connexion be- 



mcchanical act of respiration in fishes is similar to what '^u ^^!^ ^^^r"^^" 

 ^ c nanism or re- 



takes place in several reptiles, and that the motion of re- spiration and 



spiration is necessarily combined with that of deglutition. ^^^^"^^^P'^^^^ 

 This connexion between the organs however need not sur- 

 prise us, when we observe under other circumstances, and 

 fox another object, this same function of respiration ne- 

 cessarily combined in the reverse order with the act of de- 

 glutition. Thus the adult elephant cannot drink, if he do It occurs in th« 

 not make a strong expiration into his trunk at the moment^ ^^^"^* 

 of deglutition. Other functions might afford us many ana- 

 logous examples; but these considerations, though highly 

 important, would be misplaced here, and carry us too far 

 from our subject. 



V. 



Farther Experiments on the alkaline Strength of the Pro- 

 duct of the Oxigenation of Potassium^ with Observations 

 on the Nature of the alkaline Metalloids : by J. Murray, 

 Lecturer on Chemistry^ Edinburgh. 



To Mr. NICHOLSON, 



Edinburgh^ April the ist, 1811. 

 SIR, 



IN the communication inserted in (he last Number of your Object to deter- 



s, made 

 alkaline: 

 strength 



Journal, I gave an accownt of some experiments, made^^^^j^e^ *^'^"^* 

 with the view of ascertaining the comparative alkaline strength of 



