938 REPORT OF COMMIS"SIONER OF FISH AND FISHERIES. 



tlie operation may continue, tlie vapours must be removed as fast as tliey 

 are formed. To eifect this they can be absorbed by a current of water. 



" It is preferable to abstract a current of spent solution from tlie boiler, 

 and to conduct this current into the apparatus shewn at J, in which the 

 vapours may be absorbed. This ajjparatus is exactly similar in its. gen- 

 eral arraugemeut to that shewn at H, and is in free communication with 

 the same, by means of the vessel F and its two tubes h and J, consequently 

 the vapours which are formed in H arrive freely in the apparatus J. To 

 absorb them, the spent solution coming from the vaporizing condenser 

 B is conducted into the gutter j a, j a, and to the passage of which I will 

 hereinafter refer. This gutter, perforated similar to the gutter g e, g e, 

 with a multitude of holes, discharges over the length of the top tube J h 

 the solution from the first tube; it falls on to the second, and so on, thus 

 offering a very large surface for the absorption of the vapours which 

 arrive from the apparatus H. But to effect this absor^^tion it is not suf- 

 ficient merelj" to offer the absorbing surfaces to the gas to be absorbed, 

 it is necessary that the liquid should be cold, and moreover that the heat 

 l^roduced by the condensation of the trimethylamine vapours should be 

 carried off, the absorption being in direct proportion to the temperature. 

 To obtain this double result the spent solution which escapes from 

 the float vessel D is caused to pass through the tube d, h, d, &, d, &, 

 through an apparatus shewn at K, which may be called an exchanger, 

 and the action of which is hereinafter described. At the outlet 1c, a of 

 this exchanger the solution escapes by the tube A', &, 7,-, &, which conducts 

 it to a worm L, which, constantly surrounded with cold water, effects 

 the cooling of the said solution, which then enters the apx)aratus J at a 

 temperature identical with that of the water which was employed to 

 cool it in the worm L. 



"With regard to the caloric which is disengaged during the condensa- 

 tion of the trimethylamine vapours in the absorber J, it is carried off by 

 a current of water, which is caused to arrive by the cock j, c, and which, 

 running through all the tubes j &, j b, j b, carries oft' the caloric as fast 

 as it is formed. 



"To assist the distribution of the liquids over the changer from H and 

 J, they maj'^ be coated with a light tissue of cotton netting. 



" Should water be scarce in the country where the apparatus is working, 

 the water which has been used in the absorber J may be used for the 

 condensation in the condenser E, which is a very imj^ortant considera- 

 tion. Only slight excess of pressure in the trimethylamine generating 

 apparatus will result from this state of things, and consequently it is 

 always easy to set them up. 



" Eeferring again to the absorption, a portion of the vapours will have 

 been able to escape at the condensation. To avoid this inconvenience 

 the vapours and the condenser liquid which has been used in the ab- 

 sorber J are caused to descend through the tube j/, j/, which conducts 

 the whole into M. 



