MECHANICS AXD USEFUL ARTS. 73 



value will become fixed to the compost, and we may live to see 

 the time wlieii it will be found quoted in commercial price lists 

 with guano and other fertilizers. 



The amount of earth required is only 3^ times the weight of 

 the excreta, and as seaweed charcoal, though only one-fourth as 

 much would be required, would certainly cost more than earth, 

 the latter could never compete with the former except on ship- 

 board, or in cases where large bodies of earth must be transported, 

 unless the charcoal could be in some way renovated and its ab- 

 sorbent power restored. 



As charcoal can be used over several times, and then redistilled 

 with the mixed excreta, the whole ammonia product being re- 

 covered, and the charcoal thus renovated recovers its absorbent 

 power, it may be that the system of Mr. Stamford will be found 

 to possess some advantages. 



Mr. Stamford has made some interesting researches on the 

 products of the distillation of the mixed charcoal and excreta. 

 These products are, he finds, remarkably similar in composition 

 to the distillates from bones, in manufacturing boneblack. Am- 

 njonia, acetic acid, butyric acid, acetone, and pyrol are the most 

 marked products, and the charcoal produced is, he asserts, second 

 only in value to that of bones. The redistilled seaweed charcoal, 

 and the charcoal resulting from the destructive distillation of the 

 excreta, will give an increased weight of charcoal, so that, if this 

 process were adopted, the product for the city of Glasgow alone, 

 it is estimated, would be 19 tons per day. 



The uses to which this charcoal might be applied are various. 

 The system seems to have been the result of much study and 

 close thought, but we doubt whether its merits will ever prove so 

 great as to supersede the dry-earth method. — Scientific Ameri- 

 can. 



SALINE SOLUTIONS FOR STREET-WATERING. 



The superintendent of street cleansing, etc., of Liverpool, has 

 just issued his report to the Health Committee upon the trials 

 made during the past season of Mr. Cooper's street-watering 

 salts. The main thoroughfare along Lord. Church, and Bold 

 Streets, chieliy macadamized, is considered to have aftbrded as 

 severe a test as possible from the heavy traffic over it during the 

 hottest period of summer. It is stated in the report that the use 

 of these salts has been entirely successful, and be3'ond comparison 

 superior to plain water. In practical results, two water-carts with 

 the weak solution wore found equal to seven under the old system 

 upon the macadamized road ; but in jiaved streets one may be 

 -expected to do the work of five where the traffic is only ordinary. 

 Financially, notwithstanding the saving of horses and carts, it 

 appears that, at the price of 3 pounds per ton, hitherto charged 

 for the salts, no economy can be efi:ected ; but then the supply 

 has been so far in experimental quantities, and it should be stated 

 that the patentee is now prepared to deliver in quantity at 40 

 shillings. It is further considered that a reduction of 70 per cent. 



7 



