PURIFICATION OF REFUSE WATER. 



521 



If the flow of turbid water is not very strong it will be sufficient l!o 

 dig deep water-tight pits, 2 or 3, close together, as shown in the following 

 diagram : 



These pits, which should be lined with brick and be cemented or made 

 Tv'ater-tight by clay, receive the turbid water through drain pipes (of 

 terracotta) M'hich bend towards the bottom of the pit. The How of 

 water, however, is broken by a stone projecting from the side of the pit, 

 so that below this stone the water is in repose. The pipe through which 

 the water leaves the last pit is bent upward, so that any particles float- 

 ing on the water, such as oil, &c., may remain in the pit, from which they 

 are removed from time to time, and are in this way prevented from enter- 

 ing the public water-courses. Such floating particles are specially inju- 

 rious to fish, because they are in the habit of collecting anything floating 

 in the water; tar, petroleum, &c., may thus prove poisonous. 



By repeated personal observations I have become convinced that even 

 lighter organic matter floating in the refuse water has settled at the 

 bottom, and that from the third, or even from the second pit, the water 

 flowed out perfectly pure and clear. 



PURIFICATION OF WATER BY CHEMICAL PROCESS. 



This method of purifying water will, of course, be influenced by gen- 

 eral or local conditions. 



In the first place it should be unlawful to introduce any hurtful mat- 

 ter into public waters ; and it would be very desirable if the recently 

 appointed inspectors of manufactures were to give some attention to this 

 question of refuse. As soon as there is a doubtful case, it should be 

 submitted to competent chemists or health-officers, making, if necessary, 

 a last appeal to the imperial health officer. German manufiictures are 

 but too frequently carried on in a one-sided manner, excluding the chem- 

 ist who is often the only person capable of giving information or render- 

 ing aid, especially as regards the greatest possible utilization of all 

 manner of refuse. 



Such utilization is often prevented by the ignorance of manufacturers, 

 who, though well versed in everything pertaining to their special branch 

 of industry, avoid anything which does not seem to come within their 

 immediate province. It is therefore the duty of the government to take 

 this matter in hand by diftusing information and making regulations. 



Even large factories simpjy lead the refuse of soap from the washing 



