CHEMICAL SCIENCE. 251 



enables us to learn at any moment the production of sugar in a sample, the 

 sugar, when formed, being nearly insoluble in cold alcohol. Thus, when a 

 certain number of crystals have formed, if we withdraw by solution in 

 alcohol the unchanged glucose, and after dissipating the alcohol, allow it to 

 repose, crystallization recommences in the portion removed, and repetitions 

 of this experiment may be made, until after about ten months, small por- 

 tions only of unaltered glucose remain. 



Although the evidence of the conversion of the glucose, step by step, into 

 sugar, afforded by the action of alcohol, is important, the observations here 

 recorded are based upon experiments made in a similar manner, with the 

 alkaline solution of tartrate of copper, and acidulated alcohol saturated 

 with cane sugar; they leave no doubt that the normal saccharine juice of the 

 plant becomes, per se, converted into sugar, forming regular crystals of 

 large size. These crystals, by solution in water, are easily purified, losing 

 their porous structure and becoming solid, transparent, and colorless modifi- 

 cations of the rhombic prism from an aqueous solution. They are always 

 apparently more voluminous than the crystal of cane sugar, formed under 

 like circumstances, but they have all the brilliancy of cane sugar. In 

 chemical characters, the most pure crystals yet obtained show a diversity 

 when compared with our cane or palm sugar. They arc less soluble in 

 water; in sulphuric acid they do not exhibit the same depth of coloration 

 that sugar-cane does. With the copper test, a partial reduction takes place, 

 under the same conditions, where cane sugar does not produce change on 

 this agent. 



The conclusion reached is, that this sugar, wholly unlike any variety of 

 glucose or fruit sugar, belongs to a higher class, and probably will rank 

 with beet sugar, in most of its characters. 



The present is the first instance, within my knowledge, of the conversion 

 of any variety of glucose into sugar of high grade, after its extraction 

 artificially. 



Dr. Hayes further remarked, that neither the crystalline form, nor the 

 action of the polariscope, are to be relied upon in distinguishing the varieties 

 of sugar. He considered the crystalline form of the sorghum sugars, and 

 the honey sugars to be identical; the chemical properties of the sugars h 

 regarded as the only distinct proof of the several varieties. 



ON THE ACTION OF ANAESTHESIA. 



At a recent meeting of the N". Y. Academy of Medicine, Dr. Detmold 

 remarked that members would recollect that, about the year 1847, he called 

 the attention of the academy to certain propositions, which he then made, 

 proving quite conclusively that carbonic acid gas is the efficient agent in 

 causing anaesthesia. The carbonic acid may be given as such, or one of its 

 chemical ingredients may be so administered, that, finding in the blood the 

 other constituents of this compound, carbonic acid gas is generated, and 

 anaesthesia, to a certain extent, is the result. Thus we may administer oxy- 

 gen in large quantities, in the form of nitrous oxide (protoxide of nitrogen, 

 or laughing-gas), which has all the chemical reactions of oxygen, but is 

 much more soluble in water and the serum of the blood than pure oxygen, 

 and, therefore, is much more readily taken up. This compound, meeting 

 with the carbon of the blood, carbonic acid gas is formed in large quanti- 

 ties, with the production of anaesthesia to a certain extent. Or we may, on 



