83 



had detected iodine in many aquatic plants in France, such as water- 

 cress, marsh-marigold, water-lilies, reeds, various species of Carex, 

 Villarsia, Menyanthes, Myriophyllum, Ceratophyllum, Potamogeton, 

 aquatic Ranunculi, Charae, Conferva?, Callitriche, Fontinalis, Stralio- 

 tes, Scrophularia, &c. He did not find iodine in Ranunculus acris, 

 bulbosus, repens, nor Cardamine pratensis, although it was present in 

 all the aquatic species of Ranunculus and Crucifera? examined. His 

 conclusions are, — First, that plants which grow in running waters, and 

 in sheets of water sufficiently large to be strongly agitated by winds, 

 contain more iodine than those growing in stagnant waters. Secondly, 

 iodine is generally found, although in small quantity, in plants which 

 are only partially covered with water, or only during a part of their 

 life. Thirdly, plants which contain iodine when growing in water, 

 lose it when they are developed out of water. Fourthly, the propor- 

 tion of iodine observed in plants is independent of their place in the 

 natural system, and in general has no relation to specific character; 

 iodine would thus appear to be an accidental, inorganic ingredient. It 

 is present only in cases where iodine or salts of iodine are contained 

 in soil or water in which the plants grow. 



2. ' Remarks on numerous species of Diatomaceae found in Peat 

 from Cantyre ;' by Dr. Balfour. The author observed that the peat 

 is remarkable on account of its containing an immense accumulation 

 of leaves, which are comparatively unaltered in their structure. The 

 bed in which it occurs is stated by the Duke of Argyll to be an exten- 

 sive flat or plain, very little raised above the existing level of the sea, 

 full of peat-mosses, strata of clay, with vegetable stems, &c. It must 

 be of ancient date, as it is covered by clay and gravel, and there is 

 reason to believe that a peat- moss now cut away lay over it. This 

 moss, where it remains still uncut, is from ten to twelve feet in depth. 

 The forms of the leaves are well marked, and the following appear to 

 occur: — Leaves of Salix Caprea, S. viminalis or stipularis ; stems and 

 leaves of a moss; stems of grasses, and of a rush ; leaves of a heath- 

 like plant, either Empetrum nigrum or a species of Erica ; and 

 epidermis of birch, Mr. John Matthews, who had examined the 

 microscopic structure of the leaves, &c., had detected woody and 

 vascular tissue. He had also found scalariform vessels indicating 

 the remains of ferns, and had detected the cellular arrangement of 

 grasses, as well as of mosses. His investigations have shown the 

 unaltered condition of the anatomic;.! structure, and they call atten- 

 tion to the use of microscopic researches in determining the nature of 



