Dr. Rainy on the Detection of Arsenic. 77 



of the grass, causing decay ; while the fluid manure which ultimately 

 remains, after flowing through several meadows, produces the healthiest 

 and best grass. Some of these meadows are let for £30 to £50 for the 

 cutting of the grass. Six different specimens of water from the meadows, 

 of a gallon each, yielded — 



1. Water taken up immediately on its leaving the sewer, 244 grains 

 of solid matter, and 82 gi'ains in solution. 



2. Taken as it flowed from subsidence pond, 52 grains of solid matter, 

 and 87 grains in solution. 



3. Taken after having flowed over one plat, 31 grains of solid matter, 

 and 89 grains in solution. 



4. Taken after having flowed over several plats, 15 grains of solid 

 matter, and 82.7 grains in solution. 



5. Taken still farther on, 2 J grains of solid matter, and 67.2 grains in 

 solution. 



6. Taken at the sea when passing away, 2| grains of solid matter, and 

 72.9 grains in solution. 



The meadows farthest from the source of the sewage water consist of 

 poor sandy land, yet they produce better grass, in consequence of the 

 water being deprived in its progress of its grosser matter held in suspen- 

 sion. Mr. Smith observed that sewage water contains a larger propor- 

 tion and vai-iety of nutritious matter than even guano. 



Mr. Smith illustrated by diagrams the method of sewerage recom- 

 mended by him, showing the importance of having a sufficient and uniform 

 fall in the sewerage, and of using small air-tight pipes, instead of the 

 large ones commonly employed. 



\^th December, 1849. — Tlie President in the Chair. 



The following were elected members of the Society : — Messrs. John 

 Paterson Brown, Hugh Wilson, Moses Provan, Robert Walker, William 

 Mirrlees, jun. 



On the motion of Mr. Grourlie, seconded by Dr. Walker Arnott, it was 

 unanimously agreed to elect Dr. Balfour, Professor of Botany in the 

 University of Edinburgh, an Honorary Member, in consideration of his 

 eminent services to the Society dui-ing his residence in Glasgow. 



Mr. Crum proposed, on the recommendation of the Council, that the 

 next meeting of the Society should be held on the 9th proximo, and be a 

 conversational meeting, which was agreed to. The following paper was 

 agreed to : — 



XI. — On EeinscKs Process for the detection of Arsenic. By Harry Rainy, 

 M.D., Professor of Forensic Medicine in Oie University of Glasgow. 



This process consists in boiling the suspected fluid with about -jL of its 

 bulk of muriiitic acid along with cojiper. The arsenic is deposited on the 

 copper in the form of a steel-grey film. 



