SCIENTIFIC PROGRESS. 489 



organic substances, such as alcohol, various kinds of ether, grape 

 sugar, organic acids, fats, alkaloids, vegetable oils or perfumes, etc., 

 are being manufactured in a purely chemical way, and the hope is 

 well founded that in course of time we may also succeed in prepar- 

 ing directly from the elements sugars and albumins yea, even the 

 protoplasm or that organic primal substance out of which all living 

 beings are evolving. What chemistry even now is capable of 

 achieving is shown by the preparations made from coal tar of prac- 

 ticable pigments, perfumes, saccharines, and drugs. 



Finally, we must mention in this place the discovery of argon, 

 a hitherto unknown element of the atmospheric air, as well as the 

 successful preparation of acetylene by Professor Moisson. This is a 

 luminous gas which is sixteen times stronger than common gas, and 

 has five times the illuminating power of Auer's gaslight. 



Geology. As we owe to the progress in chemistry the refuta- 

 tion of the theory of a vital principle, geology in like manner has 

 disproved, chiefly through the labors of the gifted English geologist 

 Lyell (1830-33), the formerly accepted theory of great physical 

 catastrophes or terrestrial revolutions and of separate acts of crea- 

 tion, and has shown that the past of the history of our globe (which 

 in its evolutionary process advances slowly but continuously) is 

 nothing but its unrolled present. 



Paleontology. In close connection with geology is paleontol- 

 ogy, or the knowledge of the former life of our globe. This has 

 been raised to the rank of a science only during the present century. 

 Now this science has so far advanced that we can survey the gradual 

 development of the entire organic world, and find that those transi- 

 tional and intermediate forms required of trie evolutionary theory 

 are no longer missing. The vast North American plains are espe- 

 cially remarkable as having been found to be rich treasure houses of 

 such forms. 



Anatomy. Closely connected with paleontology are anatomy 

 and the discovery made in this science of the cell as the primordial 

 element or fundamental form of the whole organic world. This 

 discovery was made by Schwann and Schleiden in 1839, after the 

 microscope had been brought, through the efforts of Amici, to such 

 a perfection as to make possible by its use the more and more subtle 

 investigation of animal tissue. Through the discovery of the cell, 

 the unity, as to kind and origin, of everything living was demon- 

 strated; and it was shown that even the highest and most compli- 

 cated organisms were simply combinations of cells in a more or less 

 changed condition. Then, in 1859, Yirchow made an ingenious 

 application of the cell theory to medical science. Yirchow, in his 

 Cellular-PatJiologie, searched in the modified cell for the nature 



YOL. LII. 36 



