72i Experiments on Audition^ 



ceived with regard to the grave sounds. The higher tones of 

 glass staccados, or of an octave flute, the ticking of a watch, all 

 kinds of sibilant sounds, &c. are thus greatly augmented : the 

 experiment is easily tried, by whistling very shrill notes. A 

 still greater augmentation of the acute sounds is obtained, by 

 placing the hands formed into a concave behind the ears, and 

 by bending downwards the upper part of the auricula, so as to 

 obtain a more complete cavity. 



I will conclude with the following observation : 1 had, in con- 

 sequence of a cold, a very slight pain in my left ear ; on sound- 

 ing the regular notes of the piano-forte, C and C* were much 

 louder than the others, and the loudness was much increased, 

 by placing the hand in the manner above described to the left 

 ear. When it was pressed close, or when the Eustachian tube 

 >vas closed, the intensities of all the notes were equalized, I 

 attribute this affection to the diminished tension of the mem- 

 brana tympani, which was again increased by the operation 

 described. 



On the Petromyzon Marinus. 



On entering the harbour of Dublin a few weeks ago, we were 

 becalmed off the Hill of Howth, and to pass the tedious time 

 until a breeze sprung up, we found some lines on board, and 

 began to fish from the quarter-deck. We caught a number of 

 grey gurnet ; but our attention was particularly attracted by a 

 pull of uncommon force on one of the lines. Having rendered 

 assistance to the person who held it, we were all astonished to 

 see rise out of the water a large fish, with apparently a double 

 body, which, after floundering on the surface of the water, we 

 pulled on deck. On examining this phenomenon for a short 

 time, we were again surprized to see it separate into two parts ; 

 and then found that there were two large fish taken up on the 

 same hook, the head of one having been buried under the throat 

 of the other, to which it had firmly attached itself. When se- 

 parated by force, it wriggled about on the deck with extraordi- 

 nary strength and agility, and again darted on its prey, to which 



