THE ALUMNI JOURNAL 57 



remarkable example of physical isomerism, for when naturally 

 obtained it rotates the plane of polarization, but when artificially- 

 prepared is optically inactive. 



On oxidizinjT Sugar with Nitric Acid, Schcelc obtained an or- 

 ganic acid which he named Saccharic Acid, now called Oxalic Acid. 

 Oxalic Acid is almost universally distributed throughout the veget- 

 able kingdom. From W^ater and Carbon Dioxide, by means of 

 sunlight and chloro])hyll grains, ]ilants build up this compound: 



2CO, + H,0 = (COOH), + O 

 The acid then coml)ines with Calcium Carbonate and forms the 

 crystalline Calcium Oxalate so valuable to the pharmacognoscist 

 as a means of recognition of powdered drugs : 

 (COOH)3 + CaC03 = 

 [Oxalic Acid] [Calcium Carbonate] 

 CaCoO, + H,P + COo 

 [Calcium Oxalate] [Water] [Carbon Dioxide] 

 These crystals of Calcium Oxalate are divided into classes : Rosette, 

 Monoclinic or Cubical, Raphide or Needle-shaped, and 'Cryto-crys- 

 talline- As not only the class but even the size is peculiar to cer- 

 tain i)lants, the microscopist finds it an important element in iden- 

 tification. For instance. Rosette crystals up to 25 microns are 

 found in Buchu, up to 35 microns in Pilocarpus, up to 100 microns 

 in Gaultheria, while the Monoclinic crystals up to 10 microns exist 

 in Uvi Ursi, up to 20 microns in Hamamelis, up to 30 microns in 

 Eucal}-i)tus, and Raphide crystals occur in Phytolacca, and Crypto- 

 crystalline in Tobacco leaves. 



Because of the certainty and celerity of its action, Oxalic may 

 supplant Carbolic Acid as the favorite of suicides when the dreaded 

 phenol — on account of its ceaseless havoc among the laity — is alto- 

 gether ousted from pharmacy. Oxalic Acid can kill a human 

 being in three minutes. Because of its resemblance to Epsom salts 

 it has on several occasions been taken in mistake for that much- 

 used saline purgative. 



The only acid Scheele discovered which is called by his name 

 is Scheele's Dilute Hydrocyanic Acid (Prussic Acid), obtained by 

 him from Prussian blue. It is four or five per cent., the ofificial 

 Acidum Hyrdocyanicum Dilutum of our Pharmacopoeia being half 

 that strentgth. In the concentrated form it is a rarity to be found 

 only in the laboratories. 



Prussic Acid is found in the pits of ap])les, in the kernal of the 

 peach and in the leaves of the laurel. If these are consumed in 

 quantities, alarming — even if unexpected — illness may result. The 



