320 On ihe Hya-hya^ or Milk-tree ofDemerara. 



The usual properties of tlie milk of the Apocynea^ are dele- 

 terious, and it is rather remarkable to find an instance to the 

 contrary in this tribe ; and T do not think there is any other on 

 record. Future observations may, however, perhaps ascertain 

 similar mild qualities in other species of Tabernmnontana, 

 especially in their young branches, or when the sap is on the 

 ascent, and before it be elaborated. Among the Asclepiadese 

 of Brown, which have similar baneful properties, and which 

 many botanists indeed consider a mere section of Apocyneae, an 

 instance is also known of the milk being wholesome: I allude to 

 a plant found in Ceylon, which the natives call Kiriaghuna, 

 from Kiri {milk), and who employ its milky juice when the milk 

 of animals cannot be procured ; its leaves are even boiled by 

 them as a substitute in such dishes as require to be dressed with 

 milk : it is the Gymnema lactiferum of Brown. The young 

 shoots of several species of plants belonging to both the Ascle- 

 piadeae and Apocyneae are used as food. 



On the Formation of the Earth. By the late Sir H. Davy *. 



The Stranger On these matters 1 had facts to communicate. On the geo- 



logical scheme of the early history of the globe, there are only analogies to 

 guide us, which different minds may apply and interpret in different ways. 

 Astronomical deductions, and actual measures by triangulation, prove, that 

 the globe is an oblate sphteroid flattened at the poles ; and this form, we 

 know, by strict mathematical demonstrations, is precisely the one which a 

 fluid body, revolving on its axis, and become solid at its surface, by the slow 

 dissipation of its heat, or other causes, would assume. I suppose, therefore, 

 that the globe, in the first state in which the imagination can venture to con- 

 sider it, was a fluid mass, with an immense atmosphere revolving in space 

 round the sun ; and that, by its cooling, a portion of its atmosphere was con- 

 densed in water, which occupied a part of the surface. In this state, no 

 forms of life, such as now belong to our system, could have inhabited it ; and 

 I suppose the crystalline rocks, or, as they are called by geologists, the pri- 

 mary rocks, which contain no vestiges of a former order of things, were the 

 results of the first consolidation on its surface. Upon the further cooling, the 

 water, which more or less had covered it, contracted ; depositions took place, 

 shell-fish and coral animals, of the first creation, began their labours ; and 

 islands appeared in the midst of the ocean, raised from the deep by the 

 productive energies of millions of zoophytes. These islands soon became co- 



» Extracted from a posthumous work, entitled, " Consolations in Travel : or the Last Days of 

 a Philosopher;" by Sir Humphrv Davy, Bart, late President of the Royal Society of London, — 

 jn which views on various important topics are brought out in the form of dialogues. 



