THE PROGRESS OF SCIENCE FROM 1836 TO 1886. 517 



in a perfect network of curious cross-relationships. Lizards that were 

 almost crows, marsupials that were almost ostriches, insectivores that 

 were almost hats, rodents that were almost monkeys, have come at the 

 very nick of time to prove the truth of descent with modification. 

 Among the most interesting of these strange coincidences are such 

 episodes as the discovery in the rivers of Queensland of that 'strange 

 lung-bearing and gill-breathing fish, the barramunda, only known be- 

 fore in the fossil form as a long-extinct species, but in whose anatomi- 

 cal structure Giinther has discerned the missing link between the 

 antique ganoid type of fishes on the one hand, and the mud-fish and 

 salamandroid amphibians on the other. 



In the practical applications of biological and physiological science 

 to the wants and diseases of human life two at least deserve mention 

 here. Anaesthetics are almost entirely a growth of our half-century : 

 chloroform was first employed in operations by Simpson in 1847, and 

 the use of other similar agents is still more recent. Again, the dis- 

 covery that zymotic diseases in men and animals are due to the multi- 

 plication within the body of very minute organisms, known as microbes, 

 bacteria, or bacilli, now promises to revolutionize medical science. 

 Their connection with decomposition was still earlier detected. The 

 names of Pasteur, Tyndall, and Koch are specially identified with re- 

 searches into the nature of these tiny morbid organisms and the best 

 means of preventing or neutralizing their attacks, either on living or 

 dead matter. 



In marvelous contrast to the fragmentary and disjunctive science 

 of fifty years ago, modern science at the present day offers us the 

 spectacle of a simple, unified, and comprehensible cosmos, consisting 

 everywhere of the same prime elements, drawn together everywhere 

 by the same great forces, animated everywhere by the same constant 

 and indestructible energies, evolving everywhere along the same lines 

 in accordance with the self-same underlying principles. It shows us 

 the community of ultimate material in sun and star, in nebula and 

 meteor, in earth and air and planet and comet. It shows us identical 

 metals and gases in fiery photosphere and in electrically-heated matter 

 in our own laboratories. It shows us atoms of hydrogen or of sodium 

 pulsating rhythmically with like oscillations in star-cloud or sun- 

 cloud, and in London or Berlin. It exhibits to our eyes or to our 

 scientific imagination a picture of the universe as a single whole, a 

 picture of its evolution as a continuous process one type of matter 

 diffused throughout space ; one gravitative attraction binding it 

 together firmly in all parts ; one multiform energy quivering through 

 its molecules or traversing its ether, in many disguises of light, and 

 heat, and sound, and electricity. It unfolds for us in vague hints the 

 past of the universe as a diffuse mass of homogeneous matter, rolling 

 in upon its local centers by gravitative force, and yielding up its primi- 

 tive energy of separation as light and heat to the ethereal medium. 



