1104 WATER, SEA 



has the power of absorbing and dissolving organic matter is, of course, well known, 

 but it may be illustrated in a very simple manner, as follows : If water, from whatever 

 source, be distilled, the distillate will, of course, be fresh water, pure fresh water, but 

 it will have a peculiar, nauseous, and empyreumatic taste and odour, stronger in pro- 

 portion as the heat applied to evaporate it has been more elevated ; it is that smell and 

 taste which render it undrinkable for a while. If, when it has become sweet again 

 by long standing, which period may be hastened by agitation in the atmosphere, that 

 distilled water be then re-distilled, the distillate will be found to have acquired again 

 the same empyreumatic taste and odour as when it was first distilled. How is this ? 

 Because it will, by standing or agitation, have re-dissolved a portion of the air in the 

 room in which it was kept, and along with that air it will have absorbed whatever sub- 

 stances were present, dissolved or suspended in it, and those substances by their con- 

 tact with the heated surfaces of the still, yield an empyreumatic product, which taints 

 the distillate. On board ships, the water which is stored in for the use of crews in the 

 usual way, in the course of about a fortnight becomes putrid and almost undrinkable, 

 because the organic matter which that water contains is undergoing putrefactive fer- 

 mentation. But about a month or so afterwards the water gradually becomes sweeter 

 and sweeter, until at last it becomes drinkable again; because, eventually, all the 

 organic matter which it contained becomes decomposed, carbonic acid and water being 

 the result, and although the air of a ship's hold is none of the sweetest, snch water, as 

 just said, generally remains afterwards perfectly good and palatable ; because, the tanks 

 in which it is kept, being covered up, it is sheltered from fresli pollutions, and because 

 it is now saturated with pure air, and therefore cannot absorb that of the atmosphere. 



When the natural waters supplied to our habitations are obtained from impure 

 sources, as is unfortunately too often the case, the evils resulting from their use may 

 in some degree be remedied by putting in practice the recommendation which has 

 been sometimes made, of boiling such water previous to employing it as a beverage ; 

 unfortunately, the water being thereby deprived of air is, like distilled water, though 

 in a less degree, unpalatable and vapid and heavy ; it is, in fact, of difficult digestion ; 

 but there is something worse than that ; water which has been boiled, or which has 

 been distilled, by reason of its containing no air, has a great tendency to absorb or to 

 take that of the media where it is kept, so that if distilled water which contains no 

 air be kept in a ship's hold, or in an impure and confined place, it will absorb pre- 

 cisely the quantity of air which it can absorb, namely, 15 cubic inches per gallon, and 

 if that air be loaded with organic particles or impure emanations, it will soon become 

 foetid and putrid. The experiments of Dr. Angus Smith have proved that if a stream 

 of air which has already been breathed be passed through water, the latter will retain 

 a peculiar albuminoid matter which undergoes putrefaction with extraordinary 

 rapidity ; and the water which condenses on the cold exterior surfaces of vessels in 

 crowded rooms possesses the same character, and acquires in a short time an offensive 

 odour ; now this is to a great extent the case with the water of ordinary condensers 

 when allowed to become spontaneously aerated on board ship. Thus water, though 

 distilled, if kept in tainted rooms, will soon become foul. The only condition neces- 

 sary for distilled water not to become putrid or offensive is to saturate it with pure 

 air, because in that case there is no room left for other gases to impregnate it (at 

 least, practically speaking, and in the ordinary conditions of domestic or of ship 

 economy) and to keep it in covered vessels or tanks. 



Fig. 21 00 is a section, all on the same plane, showing the mode of action of the appa- 

 ratus, without reference to the real position of its constituent parts. Fig. 2101 is a 

 correct front elevation of the apparatus. 



1 shows the large entrance tube for the sea water : this tube is connected to a large 

 cock, communicating with the sea through the side or bottom of the ship ; or else flanged 

 to ii much smaller pipe connected with a pump, by means of whicli the apparatus is 

 supplied with water from the sea, which thus penetrates into the refrigerator 3, through 

 the tube of communication 4, and thence passes round the sheaf of pipes 15, in the 

 said refrigerator, through another communication tube 5, into the condenser 6, as 

 shown by the arrows, and up the large vertical tube 8, whence the surplus sea water 

 pumped up flows away through the pipe 9, in the direction indicated by the arrows- 4 . 

 The condenser, 6, being thus completely filled up with sea water, on opening the cock 

 10, the sea water passing through pipe 11 falls into the feed and priming box 12, and 

 thence through pipe 13 into the evaporator 14, filling it up to a certain level, regulated 

 by opening or shutting the cock 10 so as to maintain the sea water at the proper 

 level in the evaporator 14. 



3, Refrigerator. It is a horizontal case pervaded with pipes 15, placed horizon- 

 tally in it. The sea water being introduced into this refrigerator, circulates round 

 a sheaf of pipes 15, held between the caps 16, at each end of the said refrigerator, so 

 that the fresh water which has been condensed in the pipes 23, of the evaporator 14, 



