513 



to have been voracious, as would appear also from the structure of 

 the teeth ; but the points in which it differs from any one animal, 

 and resembles others belonging to classes extremely remote, occasion 

 the author to view it, with the singular productions of JsJew South 

 Wales, as one of the connecting links in the creation, formed for the 

 purpose of preventing any void in the chain of imperceptible gra- 

 dations, from one extreme of animated beings to the other. 



On an easier Mode of procuring Potassium than that which is now 

 adopted. By Smithson Tennant, Esq. F.R.S. Read June 23, 1814. 

 [Phil. Trans. 1814, p. 578.] 



The process originally discovered and described by Messrs. Gay- 

 Lussac and Thenard for obtaining potassium by means of iron, re- 

 quires that the iron should at first be intensely heated, and after- 

 wards that the alkali should be applied to il; in the heated state. For 

 this purpose a gun-barrel k required of sugn a length as ,to pass 

 through a furnace purposelyconstructed, having at its extremity a 

 second short portion of barrel neatly fitted to it by grinding, for the 

 purpose of containing the alkali ; and from which it may be made to 

 flow by means of a separate fire, to be applied by the attendant 

 operator at such a stage of the process, and at such a rate, as is 

 judged to be most advantageous. 



Since in this method, though the alkali is, in fact, soon mixed with 

 the iron, the process nevertheless requires the heat to be continued 

 for nearly an hour, the author conceived that nearly the same effect 

 might be produced merely by mixing the same ingredients previously, 

 and distilling them in the following simple apparatus. 



A straight gun-barrel, coated well at its lower part with Stour- 

 bridge clay, is filled to about one half its length with a mixture of 

 iron turnings and potash. Into the upper half of this barrel is in- 

 serted a smaller and thinner tube of iron, contracted at its lower ex- 

 tremity to a small orifice, sufficient to admit the vapour of potassium 

 to pass, and of such a length that its upper extremity may project a 

 little beyond the end of the gun-barrel ; and then both are covered 

 at the same time by a cap, which fits the gun-barrel sufficiently to 

 be closed with cement. In the top of this cap is a cork, with a tube 

 of safety for passage of gas that escapes during the operation. 



The advantage of the inner tube, in which the potassium is re- 

 ceived, consists not merely in the facility with which the product is 

 withdrawn, but in preventing an admixture of potash, wit which it 

 is otherwise liable to be contaminated. 



On the influence of the Nerves upon the Action of the Arteries. By 

 Sir Everard Home, Bart. F.R.S. Read June 30, 1814. [Phil. 

 Trans. 1814, p. 583.] 



The object of this paper is to show that the nerves which accom- 

 pany the arteries regulate their actions, and occasion different pro- 

 2 L 



