1877.] Prof. Tyndall on Hermetically -sealed Flasks. 487 



and accuracy from tides in which the greatest single coefficient is 3J 

 inches.) 



4. The mean retard of semidiurnal high water on the moon's transit is 

 about 16 h 4 m , which may be taken as the establishment at Malta. 



5. The results for the diurnal tides (whose coefficient in the mean is 

 about 0'3 inch) are somewhat discordant, but appear to exhibit a 

 periodical law of coefficients, such as is proper for them. 



The last point for examination is, the character of the non-tidal undu- 

 lations already mentioned. These, in many cases, far exceed the tidal 

 oscillations. Similar undulations at Swansea had attracted attention 

 many years ago (' Encyclopaedia Metropolitana,' " Tides and Waves" ; and 

 private correspondence with J. W. Gr. Gutch, Esq.). Lately, however, 

 the undulations of the same character in the Swiss lakes, called 

 Seiches, have been carefully examined by Dr. Eorel ; and there appears to 

 be no room for doubt that the non-tidal oscillations at Malta are genuine 

 Seiches. They appear to be formed by waves reflected from opposite 

 shores, producing stationary waves between them. The shores concerned 

 in forming the Seiches of Malta seem to be those of Africa and Sicily. 

 A Table, exhibiting the principal elements of their intervals and their 

 magnitudes, is given in the paper. 



II. c( Observations on Hermetically- sealed Flasks opened on the 

 Alps." In a Letter to Professor Huxley, Sec. U.S. By 

 Professor Tyndall, LL.D., F.R.S. Received September 21, 

 1877. 



Alp Lusgen, 18th September, 1877. 



My Dear Huxley, — Though the question of " Spontaneous Genera- 

 tion" is, I believe, practically set at rest for the scientific world, you may 

 possibly deem the following facts of sufficient interest to be communicated 

 to the Boyal Society. 



I brought with me this year to the Alps sixty hermetically-sealed flasks, 

 containing infusions of beef, mutton, turnip, and cucumber, which had 

 been boiled for five minutes in London and sealed during ebullition. 

 They were packed in sawdust, and when opened at the Bel-alp the 

 drawn-out and sealed ends of six of them were found broken off. These 

 six flasks were filled with organisms, the remaining ones were pellucid 

 and free from life. 



Two or three of them were subsequently broken by accident, but for 

 six weeks fifty of the flasks remained perfectly clear. 



At the end of this time I took twenty-three of them into a shed con- 

 taining some fresh hay, and there snipped off their sealed ends with a 

 pair of pliers. The air of the hay-loft entered to fill the vacuum produced 

 by the boiling in London. Twenty- seven other flasks were taken im- 

 mediately afterwards to the edge of a declivity, which might almost be 



2m 2 



