78 Gcippert on Fossil Plants, and on 



served after heating that the punctured vessels peculiar to this 

 family were still perceptible. Just as well preserved xoere the 

 sporangia of' Ferns ; the pollen, (()f Arum Dracunculus, 

 Ricinus communis, §t.) ,• mosses, {Hypnum splendens, intri- 

 catum, Fontinalis squamosa) ; and even Fungi, as Agaricus 

 deliciosus, Clavaria Jlava, §-c. After these successful experi- 

 ments, I was desirous to perform others with a solvent of silica. 

 In vain I tried the common solution of silica, {Kieselflussigkeit). 

 For when, after heating, the silica remained in the form of the 

 plants, the mass, as was easily understood, disappeared on being 

 cooled. I obtained a more successful result by dipping in a 

 volatile acid such as the acetic, and before the application of heat, 

 the fragment that had been soaked in a siliceous solution ; but 

 still a portion of the silica taken up by the plants was separated, 

 and so irregularly that it became impossible to recognise the 

 structure. Silico-hydi-o-Jluoric acid, prepared according to the 

 formula of Berzelius, answered my wishes better, for the fluoric 

 acid was volatilized, and the silica remained in the form of the 

 plant. Similar results were obtained with most of the other 

 earths and metals, and I generally selected combinations whose 

 acids were easily decomposed by heat, as acetate of lime, acetate 

 of magnesia, sulphate of magnesia, which were all converted into 

 carbonates ; nitrate of silver, nitrates of gold and platina, which 

 were all converted into reguline metals ; acetate of copper, which 

 was converted into brown oxide ; acetate of nickel and bichro- 

 mate of potash into olive-green oxides ; acetate of lead into yel- 

 low oxide ; manganese into metallic shining manganese ; cobalt, 

 wolfram and molybdena into oxides ; and all of them retaining 

 more or less the vegetable structure. In proportion as the num- 

 ber of vessels in a plant is greater, and therefore the quantity of 

 cellular tissue less, so much the more perfect are the results ob- 

 tained in these experiments. In very delicate portions an im- 

 mersion for a few days is sufficient, and in larger pieces a longer 

 period is requisite; but upon this subject I cannot communi- 

 cate very exact information, as I only discovered these facts a 

 few weeks ago *. 



In order to ascertain the change undergone by the organs of 

 the plants, I placed the above mentioned products in water. 



• I for the first time made public this discovery on the 6th July (1836) at 

 the meeting of the Natural History Section of the Silesian Society. 



