232 Litellisence and Miscellaneous Articles* 



-to 



proving, by Mr. Bauer's microscopic delineations, that, instead of 

 it being made of cotton, it is, in fact, linen. I had long employed 

 the microscope for the purpose of distinguishing the difference be- 

 tween linen and cotton, and in most of the statements I concur. 

 I must, however, disagree with Mr. Bauer on the point that the fibres 

 of flax are cellular ; on the contrary, when they are perfectly freed 

 from the cross fibres by which they are held together in their natu- 

 ral state, (which was most completely effected by the late Mr. 

 Lee), they are each found to be composed of one undivided cylin- 

 drical fibre, extending from the root to where they are united to the 

 leaves of the plant. I have specimens of flax so treated by Mr. 

 Lee, and which, from their beautiful glossiness, have frequently 

 been mistaken for silk. 



1 have not found that the flat fibres of cotton are uniformly 

 txi'istedy but only occasionally so, and in different degrees ; in fact, 

 many are not twisted at all. 



T am glad that the microscope is at length likely to find its due 

 estimation j and hope it will now be more frequently employed in 

 showing us things as they really are. I am. Gentlemen, 



With much respect, your most obedient servant. 

 Savoy Depot of Practical Science, Thomas Gill, 



125, Central Strand, London, Jan. 16, 1835. Advising Engineer. 



ON PROFESSOR MITCHELL S METHOD OF PREPARING CARBONIC 

 OXIDE. BY DR. GALE. 



In vol. v., p. 391, of the London and Edinburgh Philosophical 

 Magazine, we have inserted Dr. Mitchell's method of preparing 

 carbonic oxide free from carbonic acid. We have since found that 

 several of Dr. M.'s statements are erroneous, and intended to have 

 noticed them ; instead of this we copy the following observations 

 by Dr. Gale, Professor of Chemistry in New York, contained in 

 Silliman's Journal for October last. 



*< Having received No. 2. of Vol. XXV.of this Journal, containing 

 Professor Mitchell's paper on a new process for preparing carbonic 

 oxide, about the time I was to lecture on that subject before my 

 class in the College of Pharmacy, I adopted Prof. M.'s plan, and fol- 

 lowed his directions as nearly as possible, but much to my discom- 

 fiture found the gas obtained was perfectly incombustible : but I 

 should here state, that it was used immediately after preparation. 

 As gases will sometimes burn from a large orifice when they will not 

 from a smaller one, I varied the size of the aperture, but all to no 

 purpose. I then collected more gas, with * heat duly moderated,' 

 and preserved only the first and last portions, but did not succeed 

 in causing it to burn from an orifice. I then threw up, by means of 

 a syringe, some caustic potash into the receiver containing the gas; 

 a rapid absorption took place, amounting to nearly half the original 

 quantity, and the remainder was sufficiently pure carbonic oxide. 

 1 also ascertained, that if the gas, when procured, be allowed to 

 stand over cold water, and especially in broad and shallow receivers, 

 for two or three hours, so much of the carbonic acid is absorbed 



