EXTERNAL AIR 



INT KK i OR OK WARD 



.\ IK 



4 



3 



FLINTY PARTICLES 



VEGETABLE DUST 



Microscopical Examination of Dust suspended in 



INTERNAL (OR WARD) AIR. 



I. Epithelium from, the Mouth. 2. Ditto from the Skin. 3. Mineral 

 Dust, 4. Flax Fibre. 5. Striped Muscular Fibre. 6. Animal Cells. 

 7.. Cotton Fibre. 8. Unstriped Muscular Fibre u'ith Fat Globule adherent. 

 9. Fungi and Spores. 10. Woollen Fibre. 



EXTERNAL AIR. 



I. Epithflium Cell front the Month. 2. Ditto Scales from Skin. 3. Linen 

 Fibre. 4. Mineral Dust. 5. Cotton Fibre. 6. Hair. 7. Woody Fibrous 

 Tissue. 8. Woollen Fibre. 



yEGETABLE DUST. 

 I. Linen Fibre. 2. Hemp. 3. Cotton. 4. Pine Wood. 



MINERAL DUST. 

 J . Flinty Granules with sharp fdges. 2. The fame luith edges rounded off. 



' The examinations of the Ward and External Air were ; at the author' s request, 

 kindly made by Dr Wood^ House Physician, Old Royal Infirmary to wfto-tn fie is also 

 indebted > or the accompanying Sketch. 



