PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 751 



include the very same phenomenon that for the present stands 

 excluded from the first." • 



Some discussion followed, as usual, the reading of these items. 



In connection with the item on "tuning forks" on hardened 

 steel, Mr. James Harrison said he had experimented with steel 

 and found that on hardening it diminished in size. A piece eight 

 inches long on being hardened shortened one-sixteenth of an inch. 



With regard to the "Albumen" item, Mr. Joseph Hirsh stated 

 that large quantities of albumen are now made in Chicago from 

 blood of swine slaughtered there. His father uses up all the blood 

 to be had there for that purpose. This albumen is bought by 

 calico printers. Albumen used to be worth seventy and eighty 

 cents a pound; but now it is sold at about fifty cents. In Ger- 

 many eggs are sold at two cents a dozen, while here they are now 

 worth sixty cents. 



Mr. S. H. Maynard said the albumen of eggs is used in making 

 photographic paper, that from fish is entirely discarded. 



Mr. J. W. Chambers presented samples of Peabody's Sea Island 

 cotton, and read a letter in relation to it. 



The regular subject was taken up, and the following paper read: 



Manufacture of Beet Sugar ^ by Joseph Hirsh, ph. dr. 



The production of sugar from beets, and the establishment of 

 a branch of industry which has now attained huge proportions, is 

 not, cannot be, traced to a mere accidental discovery, but is the 

 legitimate result of careful and long-continued observation, study 

 and diligence, ever combined by a cold northerly climate. A 

 detailed account of the advance in the manufacture would show 

 progress made step b}^ step against the greatest prejudices, while 

 ridiculed and pronounced hopeless even by such men of science 

 as Liebig. Yet, in spite of almost insurmountable difiiculties, the 

 world did move; and wdiile France in 1829, produced 80,000 

 pounds of beet sugar, the supply in 1858, was increased to 

 98,452,182 pounds, or 492, 2G0 tons, made in GOO manufactories. 



Only so late as 1747, the German chemist, Markgraf, published 

 the results of his experiments with different roots, especially the 

 beet and sugar beet, in which he proved the presence of crystal- 

 lizable sugar, unknown or doubted until then. His discovery 

 remained a scientific curiosity merely, without bearing any practical 

 results; and it is to his talented disciple, Francis C. Achard, that 

 the credit belongs of examining anew all the plants which, in the 



