36 IOWA DEPARTMENT OF AGRICULTURE. 



the tank and about once a year such a tank would be pumped out or 

 bailed out. It should not be attempted to thoroughly clean the tank as. 

 this would destroy the organisms of purification. In a properly con- 

 structed tank there should be little or no offensive odor and even the 

 cleaning out will not be found to cause an excessive amount of odor. 



The effluent from the septic tank, even if clear, should not be con- 

 sidered as thoroughly pure water but in many cases on the farm it can 

 be led away directly into a tile drain without any further treatment. 

 Frequently it will be found that practically nothing escapes from the 

 mouth of the tile serving as overflow for such a tank. The liquid being 

 so clear that it soaks into the ground through the joints of the tile. 

 Very frequently such a tank may be all that is needed to dispose of the 

 sewage of the farm. 



However, in the case of a city plant it is usually necessary to filter 

 the effluent from the septic tank in order to secure the degree of purifi- 

 cation necessary. The filter for the city plants usually consist of large 

 beds of sand to which the sewage is applied in intermittent doses. The 

 work of purification is done by what we call "aerobic" bacteria, viz., thos"e 

 which require air and oxygen for their life and work. The sewage con- 

 tains enough of these organisms to start the beds and after a few weeks 

 they become established in countless billions in the pores of the sand. 

 As the sewage trickles by them they act upon the organic matter and 

 thoroughly purify it. As each dose of sewage disappears it draws down 

 air into the pores of the sand so as to keep the organisms alive. By 

 combined treatment in the septic tank and filters ninety to ninety-nine 

 per cent of the organic matter and nearly all of the bacteria in the sewage 

 can be removed. We are still experimenting with kinds of filters suita- 

 ble for use in connection with the sewage disposal plant for the farm 

 but we have not yet found anything simple enough to recommend for 

 general use and our work is still proceeding along this line. We believe 

 that we are on the right track but are not ready as yet to say anything 

 definite for publication. 



In conclusion let me say just a word or two about the farm home 

 of the future. I believe that in the great recent scientific developments 

 in connection with agriculture v/e have paid too little attention to the 

 farm home itself, which, after all, must be the center and principal 

 object of all our agricultural work. Why should not some attention be 

 given to the architecture of the farm home, and why should it not be 

 surrounded with a lawn laid out in accordance with the principles of 

 landscape gardening? To attend to these points may not require much 

 if any additional expenditure of money and what a difference could be 

 made in the attractiveness of our homes. The farm home to which we 

 have a right in the near future will be attractive in every way and will 

 be supplied with all the conveniences of modern life, including water 

 supply, sewerage, and furnace heat. It is even now in telephonic com- 

 munication with the market and with neighbors and even now the mail 

 is delivered daily at its door. Within a few years let us hope it will be 



