CHEMICAL SCIENCE. 235 



expensive if used on a large scale; finally, the odor of iodine is neither 

 agreeable nor unattended by inconveniences. 



Perddoride of Iron has been used for some twelve years in hospitals as an 

 antiseptic, and as a means of modifying certain wounds, and putrid or san- 

 guineous foci. Without diffusing the disagreeable odor of tincture of iodine, 

 it has, like the latter, the fault of disinfecting badly, of causing much pain, 

 and of acting violently upon the diseased tissues, besides injuring the cloths 

 which are soaked in it, even more than is the case with the coal-tar and plaster. 



Both iodine and the salt of iron just mentioned are in fact agents of 

 another order; they have rendered, and do still render important services. 

 They are certainly well worth preserving, but should not be compared with 

 the mixture of coal-tar and plaster. 



Nitrate of Lead, Creosote, and other substances which have been proposed 

 at one time or another, have not realized the expectations of their inventors; 

 their price has been too great, their employment required too much care, or 

 their action has not been sufficiently certain, that they could be advanta- 

 geously used in practice. There is, nevertheless, one of these which deserves 

 special mention, viz., chlorine. Ever since Guyton Morveau demonstrated 

 the true action of muriatic acid upon putrefying animal matters, the efficacy 

 of chlorine has been tested in almost innumerable ways. Solutions of chlo- 

 rine, of " chloride of soda," and of " chloride of lime," have rendered signal 

 services to medicine and in the cause of public health, especially since Labar- 

 raque, some thirty years since, indicated an improved method of employing 

 them. But the odor of chlorine, disagreeable in itself, is neither easily borne 

 nor devoid of inconveniences. Wounds, moreover, hardly accommodate 

 themselves to it any better than the sense of smell, whenever somewhat large 

 doses of it are required. 



In conclusion, the committee say : " In order to obtain from the process of 



with each agent, on the supposition that Boghead charcoal can be had at the rate 

 of $3.00 [= 12s.] per ton. 



Table showing the Cost of Purifying one uniform Quality of Feculent Sewage by the 



several articles mentioned. 



Boghead charcoal (coke), ... . . $3.00 



Nitric acid, 8 50 



Black oxide of manganese, . 9.25 



Chloride of lime, 10.75 



Peat charcoal, 11.00 



Subchloride of iron (imperfect), . . . . . 11.25 



Animal charcoal, . 16.75 



Chloride of manganese (imperfect), .... 17 50 



Bichloride of mercury, ........ 18.00 



Impure chloride of zinc in damp powder, . 26.00 

 Chloride of zinc in solution, as patented by Sir Wm. Burnett, 37 00 



Sulphate of copper, . . . 39.00 



The sulphates of zinc, iron, and alumina; common gypsum; sulphuric, sulphur- 

 ous, and muriatic acids; peroxide of iron, highly dried clay, litharge, and sawdust, 

 were found imperfect even when very large quantities were employed. 



Arsenious acid and creosote, on the contrary, were very active; but the danger 

 of a subsequent evolution of arseuiuretted hydrogen in the first case, and the diffi- 

 culty of diffusing an oily fluid like creosote in the second, seemed to interdict the 

 use of these substances. f. H. Storer. 



