HON. MEMBERS OF THE LINN. SOCIETY. 175 



The crude vinegar must be rectified by redistillation, and the impurities 

 separated by chemical means. This product was formerly regarded as 

 a peculiar principle, and known under the name of pyroligneous acid. 

 The woods most suited for this manufacture are the harder kinks, as 

 oak, ash, beech, birch, &c. ; pine will not answer. 



Vinegar, or acetic acid, cannot exist but in combination with water. 

 For chemical purposes it may be procured of the requisite strength and 

 purity in several ways. Before the process for procuring pyroligneous 

 acid was known, chrystalized verdigris (binacetate of copper,) was dis- 

 tilled at a high heat, and the vapors condensed in a succession of cold 

 receivers. Jt may also be procured by decomposing acetate of potash 

 with sulphuric acid. The presence of other acids with which it is some- 

 times adulterated may be detected by the ordinary chemical tests. 



A beautiful experiment illustrative of the conversion of alcohol into 

 acetic acid, may be made by placing a portion of black platina powder 

 over a saucer of vinous spirit and confining the whole in a glass re- 

 ceiver. The mutual action of the two substances will cause a consid- 

 erable increase of temperature, and in a few minutes acid vapors will be 

 seen to condense and trickle down the sides of the glass. 



The impure vinegar from wood or pyroligneous acid is extensively 

 used in the preparation of the salts of Alumina, and iron used by calico 

 printers, and for various other useful purposes in the arts ; it also pos- 

 sesses anti-putrescent properties, and may be employed to prevent the 

 decomposition of animal tissues. H. H. 



LIST OF OFFICERS AND HONORARY MEMBERS OF THE LINNAEAN 

 SOCIETY OP PENNSYLVANIA COLLEGE. 



J. G. Morris, D. D. Baltimore, Md. 



P. A. Browne, LL. D. Philadelphia., Pa. 



F. W. Melsheimer, M. D. Dover, York co. Pa. 



C. P. Krauth, D. D. Gettysburg, Pa. 



Prof. H. L. Baugher, " " 



" W. M. Reynolds, " " 



" M. L. Sloever, « " 



" C. A. Hay, " " 



>■' M. Jacobs, 

 " H. Haupt, 



S. S. Schmucker, D. D. 



H. S. Slagle, Esq., 



Samuel Forry, .11. D. (dec'd. ) 



John L. Stevens, Esq. 



Bern. W. Budd, M. D. 



