ANIMAL SUGARS. 65 



CLASS II. NON-NITROGENOUS CONSTITUENTS. 



1. Animal Sugars. 



a. Sugar of milk is an integral constituent of the milk of 

 the mammalia, and is a Yevj rare ingredient of any other fluid. 

 It has never been detected with certainty in the blood ; although 

 Simon was led to believe, from the taste, and the carbonization 

 with sulphuric acid, that he had once separated it from calves' 

 blood. Prout once found it in the liquor amnii of a cow, but 

 this is the only instance in which it has been detected in that 

 fluid. A more remarkable case is recorded by Koller,^ who 

 removed a milky-looking fluid from between the tunics of the 

 testicle, which contained sugar of milk. 



Sugar of milk may be obtained by evaporating whey to the 

 consistence of a syrup, and setting it aside for some weeks in 

 a cool place. Granular crystals of sugar of milk wdl be spon- 

 taneously deposited. In order to procure them in a state of 

 purity they require several solutions and recrystallizations. 



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

 prisms usually terminated by four-sided pyramids, which are 

 semi-transparent, and have a spec. grav. 1*543. It dissolves in 

 5 or 6 parts of cold water, and in 2*5 parts of boiling water, 

 without forming a syrup. A solution communicates a more 

 decidedly sweet taste to the tongue than the crystals them- 

 selves. Sugar of milk is unaltered by the air, loses nothing 

 at 212°, and is insoluble in alcohol and ether. At a high 

 temperature it fuses, swells up, and develops a sweetish but 

 very pungent odour. It burns with a paKsh blue flame, and 

 leaves after incineration, an ash consisting of the carbonates, 

 sulphates, and phosphates of lime and potash, amounting to 

 about "1^ of the sugar. According to Simon, the sugar of 

 woman's milk does not melt on being exposed to a high tem- 

 perature, but only becomes tough and fibrous. 



By digestion in dilute sulphuric or hydrochloric acid, or in 



' This fluid contained in 1000 parts: Butter 16-49 — casein 20-31 — sugar of milk 

 31-50— chloride of sodium 2-78 — lactate of soda 0-74 — sulphate of potash 1-51 — sul- 

 phate of soda 0-37 — carbonate of lime 0-38 — carbonate of magnesia 0-4 7 — phosphate 

 of magnesia 0-89. (Wagner's Handworterbuch, t. i, p. 25.) 



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