ykCIDS PRODUCED FROM GINGER. \'yf 



view, and he has nothing to do but exert the power he has 

 to fix it upon his paper with more rapidity, than he possibly 

 can in any other manner. 



Having now, I believe, proved that which I undertook to 

 prove, it is time to take leave of the subject. I am sensi- 

 ble, that the caniera lucida has many valuable properties, 

 which it is not my object to investigate. I was induced to 

 search for it by Dr. Wollaston's declaration, that it pos^ 

 sessed many advantages over the camera obscnra: I tried it, 

 and found it wanting. Doubtful whether the deficiencies I 

 found were in the instrument itself, or in my manner ot 

 using it, I sought for information by stating in yotir Jour- 

 nal the inconveniences that I found in attempting to use it, 

 Mr. Bate has shown, that, by trusting to the only public 

 information that has been given, I fell into some errours, 

 which he has corrected ; and, I think, enabled me to show, 

 that, whatever other valuable properties it may possess, it 

 has none that will induce an artist, who has chosen to use 

 the camera obscura in the practice of his profession, to lay 

 that instrument aside, and adopt the camera lucida in its 

 stead. 



I am. Sir, 



Yours, &c. 



No. 50, Strand, T. SHELDRAKE. 



Dec. 8, I8O9. 



HT. 



On the Acids produced by treating Ginger Root with Nitric 

 Acid. By T. Le Gay Brewerton, Fellow of the Royal 

 Physical Society^ Edinburgh, 



An No. 105 of this Journal, a new acid is announced, and z\ne\heAczciA 

 proposed to be called the zingiberic. To obtain this new announce . 

 acid, and examine its combinations with salifiable bases, 

 gave origin to the experiments below. 



Vol. XXT— March, 1810. N Exp, U 



