Constituents of Thames Mud. By Lionel S. Beale. 11 



These yellow masses have been described by Dr. Tidy in a Eeport 

 to the Conservators of the river Thames, written in the year 1881. 



The colour of these masses varies from a dull or dirty brown to 

 a bright yellow colour. Some are smooth and homogeneous in 

 parts, others rough and irregular containing particles of many 

 diflferent kinds, some of which have been associated with the yellow 

 matter from the first, while others have been added while the 

 matter was in the sewer or in the river. 



As portions of faecal matter are driven backwards and forwards 

 by the tide, besides undergoing disintegration as has been already 

 described, the opposite process of integration is also going on. The 

 collection and aggregation of particles of many different kinds to 

 form oval masses is always taking place. These composite masses 

 consist of numerous minute particles of sand, many fragments of 

 carbon, small portions of diatoms, oil-globules, fatty acids, and 

 many other things apparently cemented together by the yellow 

 viscid substance which forms an important constituent of faeces. 

 Many of these compound masses are as much as the 1/50 of an inch 

 in diameter. 



Incessant changes, mechanical as well as chemical, are con- 

 tinually proceeding in the organic matter of sewage, but, as has 

 been shown, these changes are not purely destructive and dis- 

 integrative. 



It may be said that all the animal and vegetable tissue and 

 other constituents of faeces with actual faecal matter present, do no 

 harm because they are constantly being disintegrated, while many 

 low vegetable and animal organisms live at their expense and grow 

 and multiply exceedingly and consume them. It may be said that 

 by these means and by oxidizing and other disintegrating processes, 

 all the organic matters present in sewage are gradually resolved into 

 substances which are not in the least degree deleterious either to 

 fishes and other organisms living in the water of the Thames or to 

 the inhabitants of the houses near the river. Such statements may 

 be made and supported by facts. Arguments telling in the same 

 direction may be freely admitted without the strong objections to the 

 presence of these things in a tidal river being in the slightest degree 

 diminished, much less removed. Yellow faecal masses of various 

 sizes are seen in plate I. figs. 1 h, S h h; plate II. fig. 4 h • 

 plate III. fig. 15 h; plate lY. figs. 12 h, 19. 



Fatty Matter, Oil-glohules and Fatty Acids. 



The fatty matter varied much in different specimens of mud. It 

 existed in the form of amorphous granules, in globules, and as 

 crystalhne particles probably consisting of fatty acids set free in 

 consequence of decomposition. Many compound masses were made 



