288 Linnaan Socictij. 



that the louder the sound, the gieatev is the extent of the scala cochlea 

 throughout which it is felt; an effect which will be still further aug- 

 mented by the greater vascularity of the membrane of the scalae as it 

 approaches the cupola. The author conceives that the internal ear 

 is protected from the injurious impression of very loud sounds by the 

 action of the stapedius muscle, which totally intercepts their trans- 

 mission by the ossicula to the membrane of the fenestra rotunda, and 

 whicii is impressed upon a particular branch of the auditory nerve 

 distributed upon that membrane. This view of the subject, he thinks, 

 is corroborated by comparative anatomy; the base of the scala.tym- 

 pani being particularly developed in animals easily awakened by 

 noises, as the cat, hare, and stag. The author ascribes to the mastoid 

 cells more particularly the power of transmitting sounds through the 

 bones of the head ; and denies that any sonorous vibrations can take 

 place in close cavities filled with elastic fluid. 



The function of the auditory tonometer he assigns to certain me- 

 dullarv expansions, which he conceives he has discovered at the ampul- 

 lular extremities of each of the semicircular canals. He is led to the 

 belief, that the fluid in these canals is capable of a species of circu- 

 lation, in consequence of the impulses received from the vibrations of 

 the membrane of ihe. fenestra ovalis, which is itself set in motion by 

 the chain of ossicula. This he infers from the circumstance, that the 

 common orifices of superior and posterior canals, and that of the ex- 

 terior canals, are immediately opposite to the fenestra ovalis in the 

 cavity of the vestibule, while their remote extremities are at the 

 greatest possible distance from the direction of the original impulses 

 given by the stapes. The perceptions of tone conveyed by the three 

 semicircular canals in each ear coalesce in the mind into one per- 

 ception ; nevertheless there is an advantage in this triple organ, 

 inasmuch as it may possibly be the means of our receiving perfect 

 impressions from different sounds, whether they be concords or dis- 

 cords; and hence enabling us to perceive these ([ualities, for the per- 

 ception of which the author does not see how a single organ could 

 sufl!ice. The writer, considering that, besides loudness and tone, 

 sounds are also capable of being distinguished by some other qualities, 

 thinks that these differences of quality may arise from different laws 

 of vibration. He imagines a monochord, for example, may, when 

 vibrating so as to occasion sound, perform its vibrations in very dif- 

 ferent modes of acceleration or retardation of its velocity, and impress 

 these different modes of vibration on the air and other media by which 

 the sound is transmitted to the ear. The organ for the perception of 

 these differences he conceives to be a part of the vestibulum, which 

 he styles the poiometer, and where he has discovered a cushion of 

 medullary matter, over which the lining membrane of the vestibule is 

 loosely extended, so as to be unsupported and depressed at its centre. 



LINN.EAN SOCIETY. 



March 2. — A. B. Lambert, Esq. V. P. in the chair : 

 A paper was read On the Botany of the Netherlands. By Joseph 

 Woods, Esq. F.L.S. 



March IG. — On this evening, (being the eve of St. Patrick,) 



Mr. 



