406 Miscellanies. 



in general, affected by external agents, much in the same manner as 

 the larger organic beings. 12. The microscopic animalcnla being 

 extremely light, they are elevated by the weakest currents, and often 

 carried into the atmosphere. 13. Those observers who think they 

 have seen how these minute creatures suddenly spring from inert mat- 

 ter, have altogether overlooked their complicated structure. 14. It 

 has been found possible to refer to certain limits or organic laws, the 

 wonderful and constant changes of form which some of these aniraal- 

 cula present. 15. That the organism of these animalcula is com- 

 paratively powerful, is evinced by the strength of their teeth and of 

 their apparatus for mastication ; they are also possessed of the same 

 mental faculties as other animals. 16. The observation of these mi- 

 croscopic beings has led to a more precise definition of what constitutes 

 an animal, as distinct from plants, in making us better acquainted with 

 the systems of which the latter are destitute — W. W. — Weimar. 



20. Meeting of the British Association for the Advancement of Sci- 

 ence. — Just as this No. was closing, we have received the following 

 important communications, to which by request, we give immediate in- 

 sertion. 



1. Xeiier/rom Roderick Impey MuRCHisoN,Esq.,toProf. Silliman. 



London, 16 Belgrave Square, Feb. 24, 1840. 



My dear Professor — I enclose herewith an invitation to attend the 

 next meeting of the British Association, to be held at Glasgow on the 

 17th of September next. The local authorities of that city, from 

 whom this invitation is sent, wish you to be the organ, through your 

 widely circulated and valuable Journal, of asking any Professors or 

 cultivators of science in the different states of N. America, to honor us 

 by being present at our next meeting. 



I need hardly tell you who are so well versed in British geology, 

 that Glasgow is peculiarly attractive to geologists, and that the Isle 

 of Arran alone will afford much instruction in some of the most inter- 

 esting pages of geological history. 



As Senior General Secretary of the Association, I can assure you, 

 that the greater the number of your countrymen, who may honor the 

 meeting with their presence, the higher will be the gratification of the 

 officers and council of our body, including yours, very faithfully, 



Rod. I. MuRCHisoN. 



2. Circular of the British Association for the Advancement of Science, 



addressed to the gentlemen invited to attend its next meeting. 



Glasgow, Isl January, 1840, 

 Sir — We have the honor to announce, that the next meeting of the 

 British Association for the Advancement of Science, takes place in 



