192 



DR. R. ANGUS SMITH 



shaken up witli the air in them. The sizes corresponding 

 to various percentages of carbonic acid are given in 

 Table II. 



Table II. — To be used when the point of observation is 

 " no precipitate." Half an ounce of baryta- water, con- 

 taining about 0"o8 gramme baryta. 



Air at o° C, and 760 millinis bar. 



Carbonic acid 



Volume of 



Size of 



Size of bottle, 



in the air, 



air, in 



bottle, in 



in ounces 



per cent. 



cub. centims. 



cub. centims. 



avoirdupois. 



0-03 



185 



199 



7-06 



0-04 



139 



154 



5-42 



©•05 



III 



125 



4-44 



o-o6 



93 



107 



378 



0-07 



79 



93 



331 



o-o8 



70 



84 



2'96 



0-09 



62 



76 



2-69 



O'lO 



56 



70 



2-46 



o-ii 



51 



65 



2-29 



0'12 



46 



60 



2-14 



0-13 



43 



57 



2-01 



0-14 



40 



54 



1-90 



0-15 



37 



51 



i-8i 



0-20 



28 



42 



1-48 



0-25 



22 



36 



1-29 



0-30 



19 



33 



116 



0-40 



14 



28 



1-04 



0-50 



II 



25 



0-89 



o'6o 



9 



23 



0-83 



070 



8 



22 



078 



o-8o 



7 



21 



075 



0-90 



6 



20 



072 



i-oo 



5-5 



197 



070 



In order to use this Table, first in its application to ordi- 

 nary circumstances in life, we may assume that a bottle 

 holding 5*42 ounces will not give any precipitate in the air 

 around houses if we live in a tolerably fair atmosphere. 

 To try the experiment the bottle must be very wide-mouthed, 

 so that we can put into it a rod covered with clean linen, 

 and rub the sides dry and clean ; we must then fill it with 

 the air of the place, either by blowing in air with a bellows, 

 or putting a glass or caoutchouc tube into the bottle, and 



