4 86 THE POPULAR SCIENCE MONTHLY. 



pound with the red coloring-matter of the blood, which is more 

 stable than that formed by carbonic anhydride, and cannot be readily 

 decomposed by oxygen. According to Leblanc, one volume of it 

 diffused through one hundred volumes of air totally unfits it to sus- 

 tain life ; and it appears that the lamentable accidents which too fre- 

 quently occur from burning charcoal or coke, in braziers and chafing- 

 dishes, in close rooms, result from the poisonous effects of the small 

 amount of carbonic oxide which is produced and escapes combustion, 

 since the quantity of carbonic anhydride thus diffused through the air 

 is not sufficient in many cases to account for the fatal result. The 

 commissioners, therefore, do not consider the use of water-gas as safe 

 as that of coal or naphtha gas, but they say that the addition to it of 

 petroleum-gas greatly diminishes the danger. So far as they are aware, 

 no accidents have occurred from its use in this country, although 

 there have been several in Europe. The third objection, that the 

 manufacture of water-gas is yet in its infancy, is to a certain extent 

 true, as, although it has been in use in Utica, New York, w r here the 

 works were recently burned, and is in use in one or two small places, 

 as Pougbkeepsie, New York, and the Manayunk District of Philadel- 

 phia, it has not been adopted by any of the large companies of Eu- 

 rope or America. 



By a comparison of the results obtained by the leading companies 

 in this country and Europe, some interesting facts are shown concern- 

 ing the cost of production, which, in the United States, has been 

 shrouded until now in mystery the value of the different processes, 

 the prices charged, etc. The accounts of the London companies, and 

 of the companies of several other large European cities, are published, 

 and therefore open to examination ; but, with one or two exceptions, 

 notably of the Philadelphia works, which are controlled by the city, 

 this is not the case with American companies, which are, on the con- 

 trary, careful in guarding the secrets of their business. From most 

 of them, certain items of information could be obtained by the com- 

 missioners only Tinder the promise of secrecy. The prices charged 

 consumers in Europe are generally much lower than those charged in 

 this country, and it seems that, owing to cheaper labor and better 

 prices obtained for the residuals (coke, tar, and ammoniacal liquor), 

 the cost of manufacture is considerably less. The average price varies 

 with companies and places, from $0,827 per 1,000 cubic feet at London 

 to $1.51 at Paris. The lower price given, however, is charged by only 

 one London company, the S. Metropolitan ; the prices of the other 

 companies are much higher, varying from $1.09 to $1,367. The low- 

 est cost of production, 59 cents per 1,000 feet, is readied by the 

 London company just named, and the highest, $1.21, by the Hamburg 

 company. The high cost in Hamburg is to be partly accounted for 

 by the fact that the price of labor is higher there than in any other 

 European city. In 1875 the lowest price in any of the large cities 



