204 
PROFESSOR TYNDALL ON THE DEPORTMENT AND VITAL 
sun to promote spontaneous generation*, caused me to take with me last summer to 
Switzerland a number of flasks hermetically sealed with special care and charged with 
infusions of various kinds. Eighty of them were carefully packed in sawdust in London ; 
but on my arrival at the Bel Alp, which stands at an elevation of some 7000 feet above 
the sea, I found only forty-five of them unbroken. They w r ere thus distributed : — 
Beef 12 flasks. 
Mackerel 12 „ 
Turnip 12 „ 
Fowl 9 ,, 
For ten days of the splendid summer with which we were favoured during a portion 
of last July, these flasks were exposed daily to the sunlight upon the roof of the Bel 
Alp hotel. The sky during many of these days was of a deep and cloudless blue ; and 
certainly in London the actinic rays never approached the power of those here brought 
to bear upon the infusions. The temperature for many hours of each day was about 
120° Fahr. Every evening, when the thermometer had fallen to about 70°, the flasks 
were removed and suspended above the kitchen-range of the hotel, the temperature 
generally varying throughout the night from 70° to 80° Fahr. Such variations of tem- 
perature, it may be remarked, are deemed by Dr. Bastian favourable to spontaneous 
generation. 
After the sunny weather had disappeared, the flasks were allowed to remain for three 
weeks suspended in the kitchen, with occasional exposures to the sun ; the average 
temperature of the kitchen where the flasks were hung was about 90° F. The result of 
the observations was that not one of these forty-five flasks yielded the slightest evidence 
of spontaneous generation. From first to last they all continued as limpid as distilled 
water. 
The sealed ends of these flasks were afterwards snipped off under various circum- 
stances, some on the Sparrenhorn, some on the glacier, some in the Massa Gorge, some 
amid the hair of my own head, and some in the rooms of the hotel. Many of them, 
moreover, were infected with water of various kinds — spring-water, lake-water, and 
glacier-water. It is not my object to give a detailed account of these experiments, but 
simply to say that it was not lack of nutritive power on the part of the infusions which 
prevented the appearance of organisms in the first instance; for when brought into 
contact with infectious matter every one of the flasks showed its power of sustaining 
and multiplying life. 
§ 29. Remarks on Hermetic sealing. 
A few brief remarks on this subject may, I think, be fitly interpolated here. Hermetic 
sealing during ebullition is an operation requiring some apprenticeship to perform it 
aright. The neck of the flask ought to be so narrow that the pressure of the steam 
within shall be always sensibly greater than that of the atmosphere without. This 
* Nature, vol. iii. p. 247. 
