1826.] Account of an improved Electro-magnetic Apparatus, 367 



most azote,* and more than animal bodies ; nevertheless it does 

 . 'not, under any circumstances, undergo the putrefactive ferment- 

 ation, which seems to indicate that the difference whi ch exists 

 - between azotized vegetable and animal matter, the putrefying 

 property which the latter possesses does not depend upon the 

 greater quantity of azote, but upon a peculiar arrangement of 

 the compound molecules ; crystalline force alone might suffice 

 to preserve this stability of the elements in cafein and some 

 ' other azotized products of the vegetable kingdom. Even in 

 animal substances, it may be observed that those which crys- 

 tallize, such as urea and uric acid, though much azotized, are 

 the least susceptible of putrifying. 



Article VII. 



Account of an improved Electro-magnetic Apparatus, 

 By Mr. W. Sturgeon.f 



The science of electro-magnetism, although so generally 

 interesting, yet (comparatively speaking) appears to be very 

 little understood. This latter circumstance is probably, in a 

 great measure, owing to the difficulty of making the experi- 

 ments, and the great expense attending the process ; for,, 

 besides the first price of a large battery, considerable expense 

 in acid must always attend its excitation, whenever an experi- 

 ment is attempted. Large batteries are always attended with 

 difficulty of management, and the great quantity of hydrogen 

 evolved during the process renders the use of them extremely 

 inconvenient to the operator. These are evidently great obsta- 

 cles to the experiments being often repeated, and to the science 

 being generally known. Another, and perhaps no less obstacle 

 to the advancement of this interesting science, is, that the expe- 

 riments beiiig hitherto exhibited on so small a scale, are by no 

 means calculated to illustrate the subject in public lectures; 

 for when the experimenter succeeds even to his wishes (which 

 is not frequently the case), the experiment can only be seen by 

 a very near observer, and the more distant part of the auditory 

 are obliged to take for granted what they hear reported (from 



♦ Cafein is composed of 



Carbon 46'51 



Azote 21-54 



Hydrogen 4*8 1 



Oxygen 27-14 



100-00 



Albumen contains of azote 15-705 



Gelatine 16-998 



Fibrin 19*934 



Urea 43-400 



Cafein then contains less azote than urea only, and urea putrifies less readily than 

 fibrin, &c. 



+ Abstracted from the Transactions of the Society for the Encouragement of Arts, &c. 



