Fio\ 40.—THIN DISC OF cow’s MILK, THE 120TH OF AN INCH IN DIAMETER, MAGNIFIED 
° 400 TIMES IN ITS LINEAR, AND 160000 TIMES IN ITS SUPERFICIAL DIMENSIONS. 
MICROSCOPIC DRAWING & ENGRAVING. 
CHAPTER IV. 
64. Structure of the itch insect.—65. Its habits.—66, The mange insect. 
—67. Its form and structure.—68. Defects incidental to. drawing 
with the camera.—69. Microscopic photographs.—70. Microscopic 
daguerreotypes by Messrs. Donne and Foucault.—71. Description of 
the blood.—72. Red and white corpuscles.—73. Daguerreotype^ of 
a drop of blood magnified.—74. Magnitude of the corpuscles..—/5. 
Cause of the redness of blood.—76. Corpuscles of inferior animals. 
—77. White globules.—78. White grains.—79. White globules con¬ 
verted into red corpuscles.—80. Red corpuscles dissolved.—81. 
Circulation of the blood.—82. Method of showing it in the tongue 
of a frog.—83. The arteries distinguishable from the veins.—84. The 
vascular system of the tongue.—85. Mucous glands.—86. Milk ; it.j 
Lakdner’s Museum of Science. h 97 
No, 73. 
