1314.] Peter Jacob Hjelm. 323 



21. On the art of hardening copper. 179?- 



22. Mineralogical observations on the porphyry mountains in the 

 parish of Elfdal, in Eastern Dalecarlia. 1805. 



23. Continuation and conclusion of the preceding paper. 1805. 



24. Appendix to Mr. Betnde's treatise on tile burning. 1805. 



II. Published separately. 



1. Translation of Bergman's treatise on the blow-pipe. 1781. 



2. Translation of Ferguson's history of civil society. 1790. 



3. Observations on the best method of procuring saltpetre. 1794. 



4. Instructions respecting the method of establishing saltpetre 

 works. 1801. 



5. On the preparation of indigo from the isatis tinctoria. 1801. 



6. Cause of the general diffusion of the method of restoring 

 persons apparently dead. 1791. 



7. Translation of Hume's smaller ceconomical essays. 1791. 



8. The art of manufacturing potash. 1802. 



9. Account of the Elfdal porphyry works in Eastern Dalecarlia. 

 1802. 



Article II. 



Experiments to determine the Defaile Proportions in which the 

 Elements of Organic Nature are combined. By Jacob Berzelius, 

 M.D. F.R.S. Professor of Chemistry at Stockholm. 



I. On the Difference between the Composition of Organic and 



Inorganic Bodies. 



In different preceding memoirs 1 have endeavoured to unfold the 

 laws according to which inorganic bodies combine. I have no 

 doulit that what I have advanced on this subject will be sooner or 

 later established by the experiments of other chemists. I mean to 

 attempt at present to extend these laws of chemical proportions to 

 the products of organic nature. Though this is a much more 

 difficult task than the preceding, yet 1 flatter myself that 1 havr at 

 least ascertained the most general rules of these combinations, which 

 in all probability art will never he able to imitate. 



It is evident that the existence of determinate proportions in 

 inorganic bodies leads to the conclusion that they exist also in 

 Organic bodies; but as the composition of organic bodies differs 

 uuallv from that of those which are inorganic, it is clear that 

 an essential modification must exist in the application of these laws 

 to these two different classes of bodies. 



To render the perusal of the details of my experiments less dry, 

 I shall begin by u short explanation of the conclusions which 1 con- 



x2 . 



