28 REPORT— 1864. 



Account of the Mode adopted at the Bradford-on-Avon Union for the 

 Utilization of Sewage. By W. Gee. 



The author stated that by the daily admixture of common eai-th, the excreta, liquid 

 as well as solid, of forty-five children in the two schools at the workhouse had been 

 wholly saved, with decency and without any offence, the operation being cleanly 

 and the deodorization rapid and complete. A remarkable featm-e in this method 

 (first published by the Hev. H. Moide of Dorchester) is the fact that the earth, 

 when raked out from receptacles which at Bradford are completely above the level 

 of the yards, may, if kept under cover till tolerably dry, be used over and oyer again ; 

 nor are paper fragments found to be troublesome, as they rot and become impercep- 

 tible. The result of this discovery is that ail incredibly small quantity of earth is 

 sufiicient for a large household ; tliree tons weight of earth (diy) used several times 

 over ha\Ting been the whole product of the schools in fifteen months. A sample 

 produced was quite free from smell, and looked like mere earth in small nodides 

 which crumbled on slight pressure into a very fine dust, fit for the tumip-drill or 

 for mixing with water, like guano. 



The author strongly m-ged Mr. Moule's plan upon general notice through the me- 

 dium of the Association as a mean.s, hitherto slighted, of meeting the great sewage 

 difiiculty in every dwelling in the kingdom not forming part of a close street ; 

 although the plan is not impracticable even in streets : it would be very superior 

 to the cesspools in common use forty years ago, and would in fact restore the 

 drains of towns to their legitimate purpose — the discharge of rain- and sink- water. 



On the Rate of Chemical Change. By A. Veenon Haecottet, M.A. 

 Two years ago, at the Cambridge Meeting of the Association, the author com- 

 municated to this Section a paper on certain cases of induced chemical action. In 

 following up the course of experiments upon which he had then entered, he became 

 engaged in the study of various chemical changes which take place more or less 

 slowly, and has thus been led into an inquiry as to the rate at which those changes 

 proceed. The principal case of induced oxidation, before described, was that which 

 occurs when permanganate of potassimn is added to a solution containing chloride 

 of tin and oxygen. Under these circumstances, while a portion of the tin salt is 

 oxidized by the permanganate, another portion is attacked by the free oxygen. A 

 large number of similar cases have since been investigated by Kessler. The author's 

 principal object was to determine what ratio existed between the two oxidations, 

 and in scrutinizing the conditions of the experiment it occun-ed to him to tiy whe- 

 ther the sulphate of mang-anese, formed by the reduction of the i»rmanganate in 

 the acid solution, had any influence. He found, greatly to his surprise, that this 

 fixed neutral salt has itself the power of determining the transference of oxygen. 

 Sulphurous acid, as is well known, when mixed with a large bulk of water which 

 has been exposed to the air, is but slowly oxidized, and this change proceeds still 

 more slowly when the solution is fi-eelj' acidified. But if to such a solution a 

 minute quantity of sulphate of manganese is added, the oxidation of the sulphurous 

 acid is at once determined. It is like, so far as the residt is concerned, the effect of 

 adding a drop of sulphuric acid to a mixture of chlorate of potassium and sugar. 

 Sulphate of manganese has also the power of determining the action of various 

 oxidizing agents, as well as that of free oxygen. Professor Kessler observes that 

 the cause of a phenomenon Imown to all chemists who have tried a cliameleon 

 solution with oxalic acid — namely, that the colour of the portion of solution first 

 added disappears very slowly, but that of succeeding portions more rapidlj — is that 

 the sulphate of manganese, formed by the reduction of the first portion, hastens 

 the subsequent action. Chromic acid has apparently no action upon oxalic acid in 

 a cold dilute solution. The addition to this mixture of pure suljjhate of manganese 

 determines, under proper conditions, an immediate reduction ot the chromic acid. 

 How the sulphate of manganese acts in these cases is, at present, matter for con- 

 jecture. We may compare the action of this salt in determining the union of 

 sulphurous acid and oxygen with that of nitric oxide. Perhaps in this case, as in 

 that, an alternate oxidation and reduction takes place. If we suppose that water 

 can act to a small extent upon a manganese salt as it acts upon a bismuth salt, 



