On the Secretion of the Leaves and Stems of the Ice-jylant. 377 



Wheat has been opportunely checked. 



The land is generally in fine condition for the spring crops. 



The impetus given to draining has kept the agricultural 

 labourers well-employed during the winter. 



Cattle, where healthy, have done well ; but they as well as 

 sheep have suffered from epidemics. 



From Nottingham, favoured by E.J. Lowe, Esq., F.R.A.S. 



Wheat looks very promising, and the grass in fields from 

 present appearance will be early. Apricots are nearly all de- 

 stroyed by frost, and gooseberries and currants injured. There 

 is a great bloom of plums, cherries, pears and apples. Peaches 

 and nectarines have been slightly injured by frost. 



[For the monthly values of the several subjects of research, 

 the names of the observers, and particulars of instruments 

 used, see the Registrar-General's Quarterly Report.] 



XLV. On the Watery Secretion of the Leaves and Stems of the 

 Ice-plant (Mesembryanthemum crystallinum, L,). By Dr. 

 Augustus Voelcker, Prof, of Chemistry Royal Agricult. Col- 

 lege, Cirencester*. 



A FEW months ago I had the pleasure of communicating to the 

 -^^ Botanical Society of Edinburgh the results of an examination 

 of the watery liquid in the ascidia of Nepenthes destillatoria. Those 

 present at the meeting, as well as the readers of the ' Philoso- 

 phical Magazine/ will remember that, in opposition to the state- 

 ments of most botanists who have directed their attention to the 

 subject of the watery secretions of the leaves of plants, I found 

 the liquid in the ascidia of Nepenthes to differ materially from 

 pure water, inasmuch as it contained from 030 to nearly 1 per 

 cent, of solid substances, partly organic partly inorganic. I 

 stated at that time my doubts as to the watery secretion of 

 plants being nothing but pure water, and gave some reasons for 

 this opinion ; Prof. Balfour, with whom I discussed the subject, 

 kindly furnished me with the means of investigating this point 

 still further by favouring me with fresh specimens of the curious 

 Ice-plant {Mesembryanthemum crystallinum), a plant which is re- 

 markable on account of the gland-like vesicular eminences with 

 which its leaves and stems are covered. The result of the examina- 

 tion of the fluid secreted by the leaves of this plant has fully con- 

 firmed the opinion expressed in regard to the watery secretions of 

 plants; at all events it has shown me that the secretion of the leaves 

 of the Ice-plant is not merely pure water, but water containing 

 several substances in solution. Though I was unable to determine 

 quantitatively the composition of this secretion on account of the 

 small quantity of liquid at my command — a quantity insufficient 

 * Read before the Botanical Society of Edinburgh, Jan. 10, 1850. 



PhiL Mag, S. 3. Vol. 36. No. 244.. May 1850. 2 C 



