Sept. 17, 1875.] ^15 [Sadtler. 



CONTRIBUTIONS FROM THE LABORATORY OF THE UNIVER- 

 SITY OF PENNSYLVANIA. 



No. V. 



ON A NEW OCCURRENCE OF TARTRONIC ACID, WITH SOME REMARKS ON 

 THE MOLECULAR STRUCTURE OP GLYCERIC ACID. 



By Samuel P. Sadtler. 



{Bead ^before the American PliilosopMcal Society, September 17, 1875.) 



In the Propyl series, nine normally formed acids ai-e possible, besides 

 several isomeric unsymmetrically formed ones. They are : — 



I. IV. vri. 



C.HgO, CsHeOa CsH.O, 



CH3 CH2.OH CO.OH 



CH, CH. CH„ 



CO.OH CO.OH CO.OH 



IL V. VIII. 



C,H«0. C,H«0, C,H,0, 



CH3 CH2.OH CO.OH 



(^H.OH CH.OH 6h.0H 



60. OH (^o.oH ho. on 



TIL VI. IX. 



C3HA - C3H,0, C^H.Oj 



CH3 CH2.OH CO.OH 



bo CO 60 



60. OH bo.OH bo.OH, 



and the following are the acids considered as having the molecular struc- 

 ture just given : — 



I. Propionic Acid. 

 II. Lactic Acid (of Fermentation). 

 TIL Pyruvic or Pyro-racemic Acid. 

 IV. Ethylene Lactic Acid. 

 V. Glyceric Acid. 

 VI. Carbacetoxylic Acid. 

 VII. Malonic Acid. 

 VIII. Tartroaic Acid. 

 IX. Mesoxalic Acid. 

 In one or two of these cases however, there is still a difference of 



