146 Observations on Combustion. 



Muhlenberg's Caiiccs. Remarks. 



56. C. acuta. Exactly ours. 



57. — caespitosa. Do. — A specimen named C. Oederi by some 



correspondent, is C. pallescens. 

 68. Carex } lagopus. This \s C. Fraseri, Sims, but is not con- 

 sidered certainly a Carex by Muhlenberg. 

 It is not with his Carices, but among the 

 grasses in another volume of the Herba- 

 rium, 1470. The leaves are radical, a 

 foot long and an inch wide, and flat, like 

 those of C. planiaginea, but without the 

 appearance of a midrib, striate, with fine 

 and stiff serratures. It was collected by 

 Mr. Kinn of Philadelphia, in the Chero- 

 kee coLintry. Pursh called it Mapania 

 sylvatica, Aubl., but he is supposed to 

 have been mistaken. 



This comparison shows that several species are contained in the 

 Herbarium, some of which were already described, which Dr. M. 

 has not mentioned in his work on the Grasses. 



Art. XIX. — Observations on Combustion, and the powers concern- 

 ed in that process ; by Samuel Morey. 



TO PjROFESSOR SILLIMAN. 



Dear Sir. — It is now more than twenty years since I have been 

 in the constant, I may say daily practice of making experiments on 

 the decomposition of water, by mixing with its vapor that of spirits of 

 Turpentine, and a great proportion of atmospheric air. In its de- 

 composition by explosion, the object was to obtain, for mechanical 

 purposes, a new and first moving power that should be perfectly safe, 

 and altogether lighter and cheaper than that from steam. With a 

 much less proportion of air, the object was to furnish a steady and 

 pleasant flame like that from oil or gas ; in both of which objects I have 

 succeeded. 



In the course of these experiments, I could never fail to admire 

 the wonderful, simple and convenient manner, which nature has pro- 



