4 Thomas Herbert Marsland 



hydrated specimens crumble with the pressure of the fingers. 

 When dried, some parts have a hardness about 1, others as high 

 as 3 or 4. Specimen No. IV. will scratch fluorspar quite readily. 

 The specific gravity varies from 1.25 to 1.30 in the hydrated 

 condition, and from 2.15 to 2.43 in the dehydrated condition. 



Water is given off very rapidly at the ordinary temperature, 

 and all can be driven off by continued heating at 105° C. 

 Standing exposed to the air of a room 'for ten mouths, speci- 

 men No. I. retained 20.87 per cent of water. No. III., in a 



tightly corked but unsealed bottle, 

 kept only 10.96 per cent of water. 

 No. IV., exposed to the air for ten 

 mouths, had 6.49 per cent of water. 

 The results of ten analyses, ranging 

 from 62.22 per cent to 71.30 per 

 cent gave an average of 66.58 per 

 cent of water in No. I. The other 

 specimens were not kept fully hy- 



Fig. 4. — A curious form of Daemon , . 



elix, having two transverse trunl^s. Qrated. 

 Part of the end and side of one " rhi- 

 zome" has been cut away, exposing The rCSultS of SOme of the COm- 

 the great, hollow tubes in the interior. 



In this case the great tubes are per- piete aualvses made are given in 



fectly fossilized and are not filled with I J o 



gelatinous silica, and their minute fUp cnhininprl InVilAa Tlio irnn 



structure is perfectly preserved. Diam- '"^ SUDJOlUeQ laDieS. ±ne irOU 



eter of ••rhizome" 25 cm. ,10 in.). f^^^^j ^^^ -^ ^^^^ ^^^^^ entirely 



in the ferrous condition, though some samples showed ferric 

 iron with the ferrous. It is all reported as ferrous. The 

 manganese is in the manganous condition in the silicate, and 

 in the peroxide condition in the dendrite. The condition of 

 the iron indicates the presence of some reducing matter, prob- 

 ably organic. 



From an examination of the tables, then, it may be seen 

 that this interesting substance consists of silicates of iron, 

 aluminum, manganese, calcium, and magnesium, with a large 

 excess of free hydrous silicic acid and in some parts dendritic 

 with manganese peroxide. 



Fig. 4. 



128 



