CONTENTS. . VII 



IV. Methods for the analysis of insecticides and fungicides Continued. Page. 



8. Tobacco and tobacco extract 32 



(a) Nicotin, Kissling method 32 



9. Formaldehyde solutions 33 



(a) Formaldehyde, method 1 33 



(b) Formaldehyde, method II 33 



10. Lime-sulphur dips and lime-sulphur-salt mixture 34 



(a) Total sulphur, Avery method 34 



11. Lead arsenate. (See Appendix.) 



V. Methods for the analysis of tanning materials 35 



1. Crude materials 35 



(a) Moisture in sample as received 35 



(b) Preparation for extraction 35 



(c) Moisture in prepared sample '. 35 



(d) Extraction 35 



(e) Analysis. : 35 



2. Extracts 35 



(a) Preparation of solution 35 



(b) Total solids 36 



(c) Soluble solids 36 



(d) Nontannins 36 



(e) Tannin 36 



3. Liquors 36 



(a) Preparation of solution 36 



(b) Total solids. 36 



(c) Soluble solids 36 



(d) Nontannins 37 



4. Evaporation and drying 37 



5. Acidity of liquors 37 



VI. General methods for the analysis of foods and feeding stuffs 38 



1. Moisture 38 



2. Ash 38 



3. Crude protein 38 



4. Albuminoid nitrogen 38 



(a) Preparation of Stutzer's reagent 38 



(b) Determination 38 



5. Crude fat or ether extract 39 



(a) Preparation of anhydrous ether 



(b) Determination 39 



6. Sucrose 39 



Optical methods 



(a) General directions for raw sugars 39 



(b) Preparation of reagents 40 



(c) Determination of sucrose in the absence of raffinose 40 



(d) Determination of sucrose and raffinose 41 



Chemical methods 41 



(a) Determination of sucrose by inversion and reduction 41 



7. Reducing sugars 42 



(a) Determinations requiring the use of Soxhlet's modification of 



Fehling's solution 42 



(b) Determination requiring the use of Allihn's modification of 



Fehling's solution 49 



(c) Methods for determination of copper contained in the precipi- 



tate of cuprous oxid 





