168 EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 



proved by his own and Vogel's experiments upon Amyloid, that Iodine 

 is not a special re-agent for starch only, and that generally the blue 

 colouring has no connection with chemical combination. He, however, 

 is not disposed to allow, that only the consistence of part of the mem- 

 brane regulates the absorbing power. 



Crystals and other Inorganic Deposits in Plants. The greater num- 

 ber of the white points visible on the outer integument of the bulb of 

 Muscari comosum, consist, according to Goeppert, of larger cells, which 

 are aggregations of four-sided prismatic crystals, placed nearly parallel 

 to each other, and pointed at both ends. Payer also (Froriep's Notizen. 

 No. 335, p. 65-68), has examined a number of these deposits in plants; 

 as, for instance, in the leaf-stalks of several species of Ficus, Parietaria 

 officinalis, &c., Urtica nivea, and Forskalea tenacissima. Others more 

 cylindrical, in Celtis Australia, and C. Missisipiensis, and those in the 

 leaves of Morus nigra, M. alba, and M. multicaulis. They are found 

 at the base of the hairs in Broussonetia papyri/era, and Humulus Lupulus, 

 and Cannabis sativa,a.nd are peculiarly remarkable in the leaves of Cono- 

 cephalus Naucleiflorus. A single large leaf of the Broussonetia papyri- 

 fera contains 134,000 of these concretions. Carbonate of lime is fre- 

 quently met with in these deposits, between the cells of the parenchyma 

 of the leaves, or their ribs, in the ducts of the leaf-stalk and its base. 

 It is present in these situations, even in leaves of so acid a juice, that 

 this would necessarily dissolve the carbonate of lime, were they in 

 contact. Oxalate of lime, which is usually distributed in the leaves of 

 plants, appears, as in the stems of Cactus, in transparent aggregated 

 crystals, in the form of spheroids covered with points, and enclosed in a 

 membrane, and sometimes also as octahedral or octangular prisms. 

 Raphides consist of an investing membrane filled with oxalate of lime. 

 Silex incrusts many vegetable membranes, and is seen also in the shape 

 of orbicular concretions. 



Link on the Structure of Coal* Link (Froriep's Notizen, No. 320, 

 p. 117-81) has established from comparative microscopical researches, 

 that the greater part of coal originates not from mineralized stems, but 

 from the peat or turf of the ancient world. p. 79. 



References to recent Foreign Works on the lower Cryptogamia. For 

 foreign information about the lower Cryptogamia, we refer our readers 

 to: 



TURPIN. Journal de Tlnstitut. No. 328, p. 126, " On the Penicil- 

 liam Biottii, a species of Mould which is formed in solu- 

 tions of Dextrine." 



AMID i. Atti della prima ricenione degli scientziati Italiani tenuta in 

 Pisa nell, Ottobre de 1839, Pisa, p. 157, "On the 

 Uredo Rosa;." 



* We are informed by Mr. Robert Warrington, that from frequent observation 

 of the extensive peat districts in Scotland and the north of England, he has long en- 

 tertained the opinion, that the coal formation has originated from this source, which 

 the investigations of M. Link fully confirm. Editor. 



