334 FERMENTATION ASCRIBED TO THE 



of Freiberg, and in the siliceous fossil strata of Franzensbad. 

 The whole deposit possesses a slight greenish color, and is in- 

 tersected with very fine colorless fibres of confervae. After 

 washing and drying the deposit, a residue like paper is obtained ; 

 and this, on being heated, gives distinct indications of ammonia, 

 showing that it contains nitrogen. It yields also a mass resem- 

 bling paper, which, on incineration, being treated with muriatic 

 acid, leaves behind siliceous skeletons, which preserve the shape 

 of the animal so completely, that it appears as if the original de- 

 posit itself were submitted to examination (Wohler). 



These observations are of remarkable interest, for, as Wohler 

 asks — Whence comes the oxygen gas — from the conferva? or from 

 the infusoria ? The quantity of oxygen being so large, and the 

 infusoria being in great preponderance, would lead to the con- 

 clusion that the former must be derived from these ; and yet this 

 is opposed to all analogy. The water comes out of a depth of 

 500 feet; and its sulphuretted hydrogen shows that it comes out 

 of a layer of rocks containing putrefying animal matter, which, 

 acting upon the sulphates, produces sulphuretted hydrogen; and 

 in this water is formed, with the aid of solar light, a source of 

 oxygen gas, to all appearances more abundant than we see in the 

 case of green plants. Sir B. Thompson (better known as Count 

 Rumford) published some experiments 56 years since, which are 

 of such a remarkable nature, that we give them in the author's 

 own words. Thompson found that silk, cotton, sheep's wool, 

 eider-down, and other organic substances, evolve oxygen gas, 

 when they are freed from air by washing, and then exposed to 

 sun-light in a glass globe perfectly filled with water. After two 

 or three days, the water assumed a greenish hue, and from that 

 moment the evolution of gas commenced. 



" One hundred and twenty grains of cotton, in a bell jar, 

 along with 296 cubic inches of spring water, gave out, during 

 the first four days, 2j C. I. of gas, containing hardly any oxy- 

 gen. It was not till the sixth day, when the sun was very pow- 

 erful, that the water suddenly became green, and gave out dur- 

 ing the next six days, 44£ C. I. of oxygen nearly pure. On 

 examining the water under the microscope, it was found to con- 

 tain a multitude of very minute, nearly spherical animalcules. 



