538 THE POPULAR SCIENCE MONTHLY. 



witches were burned because the death of some pigs was thought 

 to be due to witchcraft. Nowadays, probably, the cause of death 

 would appear in the death certificate of those pigs as swine fever ; 

 and many of the so-called haunted houses, by the method of Za- 

 dig, have been proved to be haunted, not by the ghosts of the 

 departed, but by bad drains. Children often adopt, quite uncon- 

 sciously, the method of Zadig. I had a good illustration of this 

 last Sunday, and I must tell you about it. Talking to a blind 

 child in the children's ward, I asked her if she knew who I was. 

 She said at once, " Yes, the doctor/' I asked her how she knew 

 that. She answered again, " Oh, nurse always says ' Hush * when 

 the doctors come into the wards." 



Now, gentlemen, if you really enter into the true spirit of 

 medical work, you will very soon train yourselves to be accurate 

 observers, and from observing human beings you will soon be 

 tempted to investigate and delight in other natural phenomena, 

 to find out your own proper place in this great cosmic system, of 

 which you are only a unit or microcosm. There is no doubt that 

 a true student of Nature has provided himself with endless sources 

 of amusement and happiness. Some of you may remember the 

 lines of Longfellow on the fiftieth birthday of the great natu- 

 ralist Agassiz : 



" And Nature, the old nurse, took 



The child upon her knee, 

 Saying, ' Here is a story-book 

 Thy Father has written for thee.' 



"And he wandered away and away, 

 With Nature, the dear old nurse, 

 Who sang to him night and day 

 The rhymes of the universe. 



"And whenever the way seemed long, 



Or his heart began to fail, 

 She would sing a more wonderful song, 

 Or tell a more marvelous tale." 



And this is the heritage of all honest students of medicine who 

 have built up their life's work on accurate observation. 



THE largest diamond in the world, the Excelsior, was discovered on the 30th 

 of June, 1893, in the mines of Jagersfontein, Cape Colony, by Edward Jorgansen, 

 inspector. It is a stone of the first water, valued at about five million dollars. 

 It was carried to the Cape under the special convoy of a squadron of lancers, and 

 shipped on a gunboat to London, where it was deposited in the Bank of England. 

 It weighs nine hundred and seventy-one carats and three quarters, or two hun- 

 dred and five grammes and a half. 



