THE VICTORIAN NATURALIST. 95 



bacteria. Cases of phosphorescence caused in some unknown 

 manner are recorded, which we now know must have been due 

 to bacteria — as, for example, the luminescence shown by meat 

 when cooled. In 1672 Boyle mentions a luminous neck of veal 

 which shone in more than twenty places, as decayed wood and 

 putrefying fish do. According to Dr. Phipson the first distinct 

 account is that given by Fabricio d'Acquapendente, Professor of 

 Anatomy at Padua, in 1592. He states that three Roman youths 

 residing at Padua bought a lamb and ate part of it on Easter Day. 

 Several pieces of the remainder which they kept until the next 

 day shone like so many candles in the dark. On examination 

 of the meat d'Acquapendente found that both fat and lean parts 

 shone, the softer parts most, but he could not give any reason 

 for it. 



Anecdotes such as these are very interesting just now, because 

 phosphorescence in meat has been attracting the attention of 

 our Melbourne butchers lately, owing to the unusual amount 

 seen this year. Almost every butcher in Melbourne and the 

 suburbs has had samples of glowing meat in his refrigerator, some 

 observing only the bone glowing, while others say that the fat and 

 lean are also luminous. 



As far as I can ascertain no cultures have been actually taken 

 from this meat, so that the variety of bacterium which infests the 

 meat has not been identified. 



Mr. J. E. Barnard (3), of the Jenner Institute of Preventive 

 Medicine, has been working for the last few years on luminous or 

 photogenic bacteria, his chief object being to determine as far as 

 possible the cause of their luminosity and the conditions under 

 which it occurs. 



The natural habitat of these organisms seems to be almost 

 exclusively sea water, and they are extremely widely spread, 

 occurring both in the tropics and in cooler latitudes, in surface 

 and deep water. In 1902 twenty-five varieties were stated to be 

 photogenic, and of these Mr. Barnard has made most experiments 

 with Fhotobacterium phosphorescens, the most widely distributed 

 and best known of all photogenic bacteria. It occurs on the 

 bodies of nearly all dead fish, and has a characteristic green 

 phosphorescent light. 



The light in all cases appears on the surface of the culture, 

 which, if grown in darkness and kept from exposure to daylight, 

 may remain phosphorescent for seven to eight weeks. Any 

 outside source of light seems to decrease the luminosity of the 

 bacteria. 



Last year, at the meeting of the Academy of Science at 

 Vienna {Nafure, 14th May, 1903), Professor Molisch, of Prague, 

 described the manufacture of his " bacterial lamp," which, on a 

 dark night, would be visible at a distance of more than sixty 



