202 The Irish Naturalist, August, 



seems remarkable that this curious substance has not been 

 more frequently observed. It has been frequently found in 

 the peat formations of Germany and Switzerland. Severa 

 interesting occurrences of Dopplerite in north-west Germany 

 have recently been recorded. At Elizabethfehn the stem of 

 a tree, imbedded in sand under peat, was found completely 

 transformed into Dopplerite. In another case a funeral urn, 

 covered with a lid, and containing some fragments of bones 

 was found filled with Dopplerite. 



When Dopplerite in this fresh jelly-like state is pressed on 

 blue litmus paper it turns the colour red. I also find that if 

 placed in water containing alkaline phenolphthalein the pink 

 colour is discharged. In contact with calcium carbonate it 

 liberates carbonic acid gas. My object in getting an additional 

 supply of the substance from Mr. Welch was to find out how 

 much carbonic acid gas a given quantity of Dopplerite liberated. 

 I ascertained subsequently that this had already been done 

 with some German specimens by Professor Immendorfif of 

 Jena. He found, in the case of the Elizabethfehn specimen, that 

 the quantity of gas liberated was such as to correspond to 70 

 per cent, of humic acid in the dry substance. In his paper 

 published in 1898^ the quantity is given as 90 per cent, but 

 I am informed by Professor Immendorff that there was an 

 error in the calculation. 



In a paper read before the Royal Dublin Society on May 

 1 8th, I have described the Sluggan specimen, and shown that 

 in chemical composition it is similar to those of German and 

 SwivSS origin. I find that the peat from Sluggan bog, im- 

 mediately associated with the Dopplerite, is very similar to it 

 in chemical composition. The difference is such as to suggest 

 that Dopplerite is derived from peat by a process of oxidation. 

 I have determined the acidity of the Sluggan Dopplerite by 

 Tacke's method, as applied by Immendorff to the Elizabethfehn 

 specimen, and I find the quantity of carbonic acid gas liberated 

 corresponds to nearly 73 per cent, of humic acid in the dr}^ 

 substance. This calculation is based on the assumption that 

 Mayer's formula for humic acid is correct, and that the acid is 

 monobasic. If the more recent results of Berthelot be taken 



'^ Mitteilungen des Vereins zt(r Forderung der Moorkultur. 



