48 DR. R. ANGUS SMITH ON THE 



Carbonic Acid iu Close Places in London {continued). 



Per centage 



by volume. 



Surrey Theatre, boxes, March 7, 12 p.m o*2i8 



Olympic, 11.30 p.m o'oSiy 



Same, 55.11 p.m o"ioi4 



Victoria Theatre, boxes, 24th March, 10 p.m o"i26 



Haymarket Theatre, dress circle, i8th March, 11.30 p.m 0*0757 



Queen's Ward, St. Thomas's Hospital, 3.25 p.m 0*040 



Edward's Ward, St. Thomas's Hospital, 3.30 p.m 0*052 



Victoria Theatre, boxes, April 4 0*076 



Effingham, 10.30 p.m., April 9, Whitechapel 0*126 



Pavilion, lo.ii p.m., April 9 (Whitechapel) 0*152 



City of London Theatre, pit, 11. 15 p.m., April 16 0*252 



Standard Theatre, pit, 11 p.m., April 16 (Strand) 0*320 



Pettenkofer informs us that the air of Munich may be 

 taken as containing about 0-05 per cent, of carbonic acid ; 

 with us it is certainly below this amount ; and if raised to 

 0*05 by breathings one would perceive it. May we con- 

 clude that such a small amount is imperceptible without 

 organic emanations ? Munich is very high j the air must 

 sweep over the whole continent to come to it; it may 

 wash up the carbonic acid, and, perhaps, oxidize the organic 

 matter. 



Air with a very small loss of oxygen is perceptibly deterio- 

 rated if its place is occupied with carbonic acid and exhala- 

 tions from the person, although we are not able to say how 

 far this is the case when carbonic acid alone is substituted 

 for this small amount of oxygen. 



On the Thames it is clearly seen that the open river is 

 purer than the streets when the water is not putrid. It is 

 purer above, at Westminster, than at London Bridge. 

 London is freer from this gas than Manchester, although 

 not equal to the parks in March and April, when the ex- 

 periments were made. When the new sewers are complete, 

 the difference will probably be perceptible. 



These analyses indicate that a very minute amount *of 

 carbonic acid shows deterioration of air sufficient for the 



