TRANSACTIONS OF SECTION B. 691 
On mixing in the above proportions in benzene solution no apparent change took 
place even on prolonged heating, but the graduated addition of ligroin to the solu- 
tion led to the separation of fine long crystals, which are very friable, of the 
compound Si(NHPh),,2EtNCS, and later of another addition compound in 
small plates which consisted of Si(NHPh),,EtNCS, but no trace of the ethyl- 
phenyl-urea. , ‘ 
The solvent benzene was then discarded and the requisite materials were heated 
in pressure tubes. 
Up to 140° ©. the addition compounds only were produced, but at 160° further 
change was obtained, and a yellowish fluid mass was produced, which remains a very 
viscid liquid at ordinary temperatures, and can be kept in this state for many 
months. 
Benzene dissolves the viscid mass, which is reprecipitated in oily droplets, but 
no trace of the urea separated. On redissolving in benzene and adding a small 
proportion of alcohol to the liquid, decomposition was obtained, and crystals of the 
ethyl-phenyl-urea separated. 
It is evident, then, that the primary interaction anticipated occurs at 160°, but 
that the urea formed at once unites with the silico-phenyl-di-imide to form: 
NHPh 
Si(NPh),,208 
\ NHEt 
This tendency of the silicon amide to unite with urea is similar to that which I 
found the Si haloids to possess many years ago, and the very viscid liquid in the 
above instance is not unlike the compound SiBr,,8CSNH,,NHC,H., which flows 
so slowly that nearlyamonth is required at ordinary temperatures for the liquid to 
descend from one end of a vertical tube to another. 
9. Report on recording the Results of the Chemica! and Bacterial Exami- — 
nation of Water and Sewage. See Reports, p. 255. 
10. Intermittent Bacterial Treatment of Raw Sewage in Coke-beds. 
By Professor Frank Ciowss, D.Sc. ; 
The above process as originally experimentally carried out by the London County 
Council was applied to the effluent from chemical treatment only. The process has 
now been applied to raw sewage, screened through coarse gratings. More recent 
experience of over twelve months’ treatment in beds of varying depth has proved 
that when coke fragments of about the size of walnuts are used, the suspended 
feecal matter wholly disappears, together with an average of about 50 per cent. of 
the dissolved organic matter. A further treatment in asecond similar bed removes 
an additional 20 per cent. of the dissolved organic matter. It has been found 
sufficient to leave the sewage in contact with the coke for about three hours, and 
then to give the coke an exposure to the air in its interstices of about seven hours’ 
duration. 
The depth of the experimental coke-beds has varied from 4 to 13 feet in different 
pee ents and this variation has in no way affected the degree of purification 
ellected. 
On no occasion has either the coke or the effluent been foul, nor does the 
effluent become foul when it is allowed to stand in either open or closed vessels, 
provided that it is not sterilised after it has left the coke-bed. 
The amount of sewage which can be treated by the coke-bed 13 feet in depth, 
and with two fillings per day, amounts to three and a half million gallonsper acre. 
This amount, however, undergoes gradual reduction, owing to the accumulation in 
the filter of matter from the sewage which appears to consist almost wholly of 
cellulose. This matter is mainly the chaff derived from the horsedung of the 
Yr2 
