88 EXAMINATION OF WATER FOR ORGANIC MATTER. 



that there is much remaining which demands more time 

 and space than is everywhere conveniently found. Time 

 and space, although by many treated as mere forms of 

 thought, are expensive in Lancashire. 



The following may be regarded as a summary of the 

 results required for sanitary purposes : — 



1 . Quality of the organic matter. 



2. Condition of the gases of decomposition. 



3. Organic matter: easily decomposed organic matter, 



and slow to decompose. 



4. Nitrates as remnants of organic matter. 



5. Nitrites. 



6. Chlorides, with precautions as indicating animal 



sources when greater accuracy is wanted. 



7 . Oxygen of the dissolved air, as indicating the activity 



of the decomposition. 



8. Total organic matter. 



This the author found by weighing. 



9. The usual inorganic analysis, to be spoken of in a 



second paper. 



The author considered that for purely sanitary purposes 

 the Nos. I, 2, 3, and 6 were the most important. 



The organic matter may be divided into many parts — 

 nitrogenous into several parts, and carbonaceous into 

 several. The total nitrogen has been taken by Dr. Frank- 

 land very carefully, and the mode of taking oxides of 

 nitrogen improved. The division into separate parts has 

 been begun by Wanklyn. The carbonaceous has not been 

 much studied of late years. 



