SUGAR OF MILK. 131 



12 atoms carbon, . 9*0 or per cent. 40' 

 12 atoms hydrogen, =1*5 ... 6-6(5 



12 atoms oxygen, = 12- ... 53-34 



22-5 100,00 



I found that, by combining it with certain bases, it might be 



deprived of another atom of water, and thus reduced to 



12 atoms carbon, = 9* or per cent. 42.11 



11 atoms hydrogen, = 1-375 ... 6-43 



11 atoms oxygen, = 11- ... 51-46 



21-375 ... 100- 



Thus it is identical with grape sugar in its constitution. Hence 

 the reason why diabetic urine is so apt to ferment and evolve 

 alcohol. 



SECTION IV. OF SUGAR OF MILK. 



Sugar of milk may be extracted from whey in the following 

 manner : Evaporate the whey to the consistence of a syrup, and 

 set it aside for some weeks in a cool place. Granular crystals 

 of sugar of milk will be deposited. To obtain it pure we must 

 redissolve it in water, and crystallize it a second time. And this 

 process must be repeated two or three times. 



Fabricius Bartholetti, an Italian, was the first European who 

 mentioned this sugar. He described it in his Encyclopedia 

 Hermetica-Dogmatica, published at Boulogna in 1619;* but it 

 seems, from what Haller says, to have been known in India long 

 before that time. It is manufactured in large quantities in 

 Switzerland, from which country all the sugar of milk of com- 

 merce comes. The person who chiefly contributed to make su- 

 gar of milk generally known, was Ludovico Testi, who gave it 

 out as an invention of his own, and sold it as a powerful remedy 

 in the gout and other diseases. He was a physician in Venice, 

 where he died in 1707. After his death Valisneri published 

 the process which Testi employed in extracting his sugar from 

 whey. 



Sugar of milk is white, and crystallizes in right four-sided 

 prisms, usually terminated by four-sided pyramids. It has a 



* According to Beckman, he called it manna, seu nitrum seri lactis. His. 

 tory of Inventions, ii. 494. 



