:;os 



ON PKESERVING THE BALANCE BETWEEN ANIMAL AND VEGETABLE ORGANISMS. 



[1854, 



to a second boiler of ihe same kind. In the same year the 

 probability of its success under a brewing copper was discus ed. 

 There was no doubt, from the former experiments, as to its 

 capabilities for raising Bteam or for evaporation ; but with a 

 brewing copper provision bad to In- made for a pro - i i the 



manufacture al st peculiar to it. The contents "1' the copper 



have to be turned oul several times in the course of n bn wing, 

 rendering il necessary to " bank up" the fire thoroughly, to protect 

 the bottom of the copper, until refilled with wort or water. It 

 was feared that the machinery would interfere with this being 

 done effectually: it was tried, and with the same success as with 

 the steam boilers. The remainder of the coppers and boileis 

 were afterwards altered. The total cost of the fourteen furnaces, 

 including brickwork, had been about £3000. The consump- 

 tion of coals in the establishment was G000 tons per annum. 

 The savin" in the coal account, since the introduction of the 

 patent to July 1st of the present year, had been £8338, from 

 which must be deducted for casualties, and sundries, say £350. 

 The above economy had not arisen from less weight of fuel 

 consumed, but owing to the screenings or dust of coal only 

 being required for the furnaces. It would appear at first sight 

 that the wear and tear of a machine, apparently so complicated, 

 must exceed the expense of the common fixed bars. This, 

 however, had not been found to be the case, and it need not be 

 so if ordinary care were given to the machine, and a periodical 

 examination such as any other machine of equal value and pro- 

 ducing equally important results would receive. Within the 

 last week a set of bars, which bad been in use since May, 

 1849, had been renewed, for the first time; and three-fourths 

 of the old bars were being again used for another furnace, 

 where the boiler was of less importance than the one from 

 which they have been removed. 



On preserving Ihc Balanee lietwecn the Auimnl and Vegetable 

 Organisms ill Sea Water* 



By Robert Warington.* 



In the published notices of my experiments of 1 849, to main- 

 tain the balance between the animal and vegetable organisms 

 in a confined and limited portion of water, the fact was 

 demonstrated, that, in consequence of the natural decay of the 

 vegetation, its subsequent decomposition and the mucus-growth 

 to which it gave rise, this balance could be sustained only for a 

 very short period, but if another member were introduced, which 

 would feed upon the decaying vegetation and thus prevent the 

 accumulation of these destructive products — a function most ad- 

 mirably performed by the various species of water-snail — such 

 balance was capable of being continuously maintained without 

 the slightest difficulty; and I may add, that the experimental 

 proof of this has now been carried on, in a small tank in the 

 heart of London, for the last four years and a half, without any 

 change or disturbance of the water; the loss which takes place 

 by evaporation being made up by rain or distilled water, so as to 

 avoid any great increase of the mineral ingredients originally 

 present. It follows then, as a natural deduction, from the suc- 

 cessful demonstration of these premises, that the same balance 

 should be capable of being established, under analogous circum- 

 stance, in sea water. And in a paper published in January, 



i ',11 i tted that I was, at that time, "attempting the same 

 kind of arrangement with a confined portion ofsea water, em- 

 ploying some ol • >"■ green sea-weeds lor tie- vegetable member 

 of the circle, and the common periwinkle as the representative 

 of the water snail.'' 



The sea water with which the experiments I am about to 

 detail were conducted, was obtained through the medium of one 

 of the oyster-boats at the Billinj b market, and was 



taken from the middle of the English Channel. 



My first object was to ascertain the kind of sea-weed best 

 fitted, under ordinary circumstances, for keeping the water clear 

 and swtet, and in a sufficiently oxygenated state to .sustain ani- 

 mal life. And here opinions were at variance, tor one naturalist 

 friend whom I consulted, advised me to employ the Rhodosperm- ; 

 another stated that it was impossible to make the red weeds 

 answer the purpose, as he had tried them, and strongly recom- 

 mended the olive or brown colored Algae; while, again, others 

 thought that I should be more successful with those which had 

 in theory first suggested themselves to my own mind, nami ly 

 the Chlorosperms. After making numerous unsuccessful ex- 

 periments with both the btown and red varieties of Algae, I was 

 fully convinced that, under ordinary circumstances, the green 

 weeds were the best adapted for the purpose. 



This point having been practically ascertained, and some good 

 pieces of the JUnleromorpha and Ulva latiisima in a healthy 

 state, attached to nodules of flint or chalk, having been procured 

 from the shore near Broadstairs, several living animal subjects 

 were introduced, together with the periwinkle. Everything pro- 

 gressed satisfactorily, and these all continued in a healthy and 

 lively condition. 



My first trials were conducted in oue of the small tanks which 

 bad been used for fresh water; but as it was necessary, during 

 the unsuccessful experiments with the brown and -red sea-weeds, 

 to agitate and aerate the water, which had been rendered foul 

 from the quantity of mucus or gelatinous matter generated 

 during the decay of their fronds, until the whole bad become 

 oxydized, and the water rendered clear and fitted for another 

 experiment, it was, therefore, for greater convenience, removed 

 into a shallow earthern pan and covered with a laige glass shade 

 to protect the surface of the water, as much as posssble, from 

 the dust and soot of the London atmosphere, and at the same 

 time impede the evaporation. In this vessel then I had succeeded 

 perfectl}' in keeping a large number of beautiful living speci- 

 mens in a healthy condition up to the close of 1852. I therefore 

 gave instructions for the making of a small tank, as a more per- 

 manent reservoir, and one more adapted for carrying on my 

 observations and investigations on the economy and habits of the 

 inhabitants. 



From the experience I had obtained in my experiments with 

 the freshwater tank, I was induced to modify slightly the con- 

 struction of this vessel ; thus, at the back, or part towards the 

 light, the framing was filled with slate in the same way as the 

 ends and bottom; for I had found that the glass originally em- 

 ployed, verv soon became covered with a confervoid growth 

 which had an unpleasing appearance to the eye, and in conse- 

 quence of which I had been obliged to paint the glass on the 

 exterior, to prevent this growth from increasing to too great an 

 extent. It was also an unnatural mode of illumination, as all 

 the light should pass through the surface of the water. The 



* Communicated to the Alhenmum by the Author, having been read 

 at the Hull Meeting of the British Association. 



f Gardeners' Botanical Magazine and Garden Companion. January, 

 1852. 



