376 Aids to Microscopic Inquiry. 



AIDS TO MICROSCOPIC INQUIRY.— No. VIII. 



Honey. 



Among the objects which are common in family stores, honey 

 may he mentioned as capable of affording considerable micro- 

 scopic entertainment. 



The bees obtain from the nectaries of flowers a number of 

 substances which may be recognized in honey — a substance 

 composed of different kinds of sugar, a small quantity of gum, 

 mucilage, a little wax, an acid, pollen grains, etc. 



Sugars are compounds of carbon, hydrogen, and oxygen. 

 Cane sugar, or the sugar in common household use, consists of 

 twelve parts of carbon and eleven each of hydrogen and oxygen. 

 It is very soluble in water, crystallizes in four or six sided rhom- 

 boidal prisms, and acts upon polarized light so as to produce 

 a right-handed rotation.* 



If the elements of water — one equivalent of oxygen and 

 one of hydrogen — are added to cane sugar, Fruit Sugar is pro- 

 duced, which does not crystallize, is more soluble in dilute 

 alcohol than cane sugar, and produces left-handed rotation of 

 polarized light. In this sugar we have twelve equivalents 

 each of the three components — carbon, hydrogen, and oxygen. 

 A third kind of sugar contains two equivalents of water added 

 to fruit sugar. This is Grape Sugar, found in dried fruits. It 

 crystallizes in cubes or square tables, is less soluble than cane 

 sugar in water, but more so in alcohol, and produces right- 

 handed rotation. Another kind of sugar, Sugar of Milk, 

 contains fourteen equivalents of carbon, nineteen of hydrogen, 

 nineteen of oxygen, together with five equivalents of water. 

 It crystallizes in four-sided prisms, is not, like those previously 

 mentioned, directly susceptible of alcoholic fermentation, and 

 produces right-handed rotation. There are several other sugars, 

 which will be found described in Miller's Chemistry, from which 

 the preceding information is condensed. 



* Suppose the experimenter to use two Nicol's prisms, one as polarizer and 

 the other as analyzer, bodies capable of inducing circular polarization -will, 

 when inserted between the prisms, twist the plane in which the light vibrations 

 take place. The explanation given in Ganofs Physics, translated by Atkinson, 

 is as follows ; — "When a ray of homogeneous light traverses the first Nicol, it 

 becomes polarized in a plane at right angles to the principal section. Its vibra- 

 tions are all in the plane of the principal section, and therefore are not transmitted 

 by the second Nicol when the planes of the two principal sections are at right 

 angles to each other. But by passing through a plate of quartz (a substance 

 capable of producing rotation) in the direction of the axis this is changed : the 

 plane of vibration experiences a uniform rotation in such a manner that its path 

 becomes that of a screw rotating round the axis of the crystal." Some substances 

 cause this screw to have a right-handed twist and others a left. 



