REPOttT ON MINERAL AND THERMAL WATERS. 33" 



Nevertheless, the observations I have myself made in some 

 of the very same localities as those visited by M. Anglada, the 

 substance of which is given in the Limiean TrunMictions* , lead 

 me to conclude, that the glairine of M. Anglada is frequently, 

 and therefore justify me in suspecting that it may be always, 

 generated at or near the surface, by the rapid growth of certain 

 lower tribes of organic beings. 



At Greoulx I remarked large patches of it hanging from the 

 sides of a highly inclined rock, over which the water of that 

 thermal spring had descended. 



Now if it had been a chemical precipitate from the waters, 

 this could not have happened ; but supposing it an organic 

 matter, whose gi'owth was favoured by the temperature or the 

 constitution of the spring, its presence therein is not more diffi- 

 cult of explanation, than that of Algfeon the face of a precipitous 

 cliff. 



Moreover, the specimens of glairine which I collected always 

 presented under the microscope, in some part or other, an or- 

 ganic structure. 



It is indeed true, that I detected traces of what appeared to 

 be the same substance in the water of Barege fresh drawn ; but 

 it being admitted that, like many other organic matters, glairine 

 is slightly soluble in water, and more so in hot than in cold, 

 its presence there may be explained, if we only suppose that 

 its growth proceeds, not only in the open air, but likewise in 

 those fissures and cavities underground through which the 

 water has to pass. 



Berthierf also, who has considered this subject in a memoir 

 on the Hot Springs of St. Nectaire, declares that he has never 

 found this organic matter in waters taken from the fountain-head, 

 and corked directly afterwards, but that it makes its appearance 

 after a very short exposure of the water to air and light. Though 

 this remark may not be universally true, the larger deposits of 

 glairine, I believe, always arise in water that has been exposed 

 to the atmosphere. 



In short, there seems no insurmountable difficulty, in the way 

 of om- attributing the existence of glairine everywhere to the 

 growth of organic bodies, such as should reconcile us to the 



tion. It is a slimy mass formed out of a great number of parts, which for the 

 most part arose from the decomposition of plants and animals, especially In- 

 fusoria. 



It is plain from this, how necessary it is that the chemist should ascertain the 

 homogeneous nature of any substance which may be suspected to be organic, 

 before he submits it to chemical analysis. — Poggendorft's Aunulen, 1836. 



* Vol. xiii. part i. \ Annales des Mines, vol. vii. p. 215. 



VOL.V.— 1836. D 



