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A N
ACCOUNT
O F A
Useful DISCOVERY
T O
Diftiil double the ufual Quantity of S e a- Water, by blowing Showers of Air up through the Distilling Liquor;
and
An Account of the great Benefit of Ventilators in many Inftances, in preferving the Health and Lives of People, in Slave and other Tranfport Ships, which were read before the Royal Society .
ALSO
An Account of the good Lffedt of blowing Showers of Air up through Milk, thereby to cure the ill Tafte which is occahoned by fome Kinds of Food of Cows*
By STEPHEN HALES, D.D. F.R.S,
Member of the Royal Academy of Sciences at Paris ,
. AND
Clerk of the Clofet to Her Royal Highness the
Princess of Wales .
The Second Edition.
With an APPENDIX
In which is an Account of fome farther confiderable Improve¬ ments made in the Method of procuring Plenty of Fresh- Water at Sea, viz. three Parts in four more than in the common Methods of Diftilling : Alfo a farther Account of more Inftances and Proofs of the good Effeft of Ventila¬ tors in Ships: As alfo of the curing, in a few Minutes, the ill Take of Turnip Milk, and of mufty Liquors. Alfo, with great Eafe, prefently to make Cream or Milk Sillabubs, viz. by blowing Showers of A: k up through them.
LONDON:
printed for R i c h a r d M a n b y, in the Old-Bailey , near Ludgate-HilL M.DCC. LVI.
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A N
ACCOUNT
O F T H E
i ' .
Great Benefit of blowing Showers of Fresh Air up thro’ Distil¬ ling Liquors.
great Importance of hav- if ing a fufficient Supply of frdli -iL Water in Ships, has been the
, , , v
Occafion of many laudable Attempts to make Sea-water frcfh and wholfome 5 but all the Attempts and Difcoveries hitherto made, have laboured under this great and material Obje&ion, viz. the great Quan¬ tity of Fuel that was necefiary to diftiil, with a flow Progrefs, a fmall Quantity of Water, by any Methods of Diftillation hi-
A 2 therto
4 To make Tlenty of
therto known. But I have lately happiljv mod unexpe&edly, difoovered an eafy and effectual Method to diftiil great Quantities of Water with little Fuel > which I was led to by the following Incidents, viz, Mr. Shipley, Secretary of our Society, for the Encouragement of Arts , Manufac¬ tures and Commerce , brought me acquaint¬ ed with Mr. William Baily of Salisbury- Court, the Author of many ingenious Con¬ trivances 5 who {hewed me, in a fmall Mo¬ del of a Tin Vefliel, a Method, by which, he has happily increased the Force of the Engine to raife Water by Fire, viz,, by lifting up fome of the boiling Water, at every Stroke, by means of a conical Veffel, with fmall Holes in it, full of Tow $. whereby the Quantity of the afeending Steam or Wreak was confiderably increa- fcd. This led me to think, that a greater Quantity of Liquor might alfo by this Means be diftilled $ but on Trial I found the Increafe to be only one twelfth Parr, tho’ confiderable in the expanded Form of a Steam. Hence I was led to try what would be the Effedt of caufing an incef- fant Shower of Air to afeend thro’ the
boiling
Fresh Water at SEA. ^
boiling Liquor in a Still 5 and this, to my Surprife, I found on Trial to be very con¬ siderable. There was another Circum¬ stance alfo, which probably conduced to lead my Mind ;to this Thought, viz. A« bout fix Months before, Jvlr. Littlewood, a Shipwright at Chatham , came thence purpofely to .communicate to me an inge¬ nious Contrivance of his, foon to Sweeten Stinking Water, by blowing a Shower of frefh Air thro" a Tin Pipe full of Small Holes, layed at the Bottom of the Water. By this means, he told me, he had Sweet¬ ened the Stinking Bilge Water in the Well of Some Ships ; and alfo a But of Slinking Water in an Hour, in the Same manner as I blew Air up thro' Corn and Gunpowder, as mentioned in the Book on Ventilators .
2. The Method, which I uSed to blow Showers of Air up thro’ the diftilling Wa¬ ter, was by means of a fiat round Tin Box, fix Inches Diameter, and an Inch and half deep ^ which is placed at the Bottom of the Sciil, on four Knobs or Feet half Inch high, to make room for the Liquor to fpread over the whole Bottom of the
A 3 Still,
6 To make Tlenty of
Still, that the Heat of the Fire may conic at it. In larger Stills this Box muft be proportionably larger, and have higher Peer. And whereas the Mouth of the Still is too narrow, for the Tin Box to enter, which Box ought to be within two Inches as wide as the Bottom of the Still $ therefore the Box may be divided into two Parts, with a Hinge at one Edge or Side, and a Clafp at the other, to fix it together, when in the Still. This Box muft be of Copper for diftilling Sea-wa- water 5 mine was made of Tin for other Liquors alfo. The Air-pipe, which pafles thro’ the Head of the Still, will help to keep the Air-box from moving to and fro by the Motion of the Ship 5 or, if that fhould not be found fufficient, 3 or 4 Email Struts may be fixed to the Sides of the Air-box. They muft reach to the Sides of the Still. The Cover and Sides of the Air-box were punched full of very fmall Holes, one fourth Inch diftant from each ether, and about the twentieth part of an Inch in Diameter. On the Middle of the
i
Cover or Lid of this Air- box, was fixed a JSToill more than half Inch wide,, which
Fresh Wa ter at S E A. f
was fitted to receive, to put on, and take off the lower End of a Tin Pipe, which was twenty Inches long, and palled thro' a Hole in the Head of the Still : four Inches of the upper end of this Pipe were bent to a Crook, almoft at a right Angle to the upright Stem, in order thereby to unite the Crook to the widened Nofe of a Pair of Kitchen double Bellows, by means of a fhort Leathern Pipe of Calves-skin. See Fig. i ft. This Tin Air-box, and many more of them for other Perfons, were made by Mr. Ted<way , Tinman, over-a- gainft the Meufe-Gate , Charing- Crofs.
3. The double Bellows were bound faft to a Frame, at the upper Part of the Iron Nofe, and at the lower Handle, in order the more commodioufly to work them. And that the upper Half of the double Bellow^ may duly rife and fall, in order to caufe a conftant Stream of Air; (befides the ufual contracting fpiral Springs within fide) fevc- ral flat Weights of Lead muft be laved on the upper Part of the Bellows, near the Handle, with a Hole in their Middle, to fix them on an upright Iron Pin fattened on the
A 4 BeH'
*
4
8 7 o make Plenty of
f Bellows : That by this Means the Weights may the more commodioufly be put on or taicen Gff. For, according to the different Depths of the Liquor in the Still, fo will the Force of the included Air^ againft the upper Board of the Bellows, be more or kfs. Thus, fuppofing the Depth of the Water in the Still to he twelve Inches \ from the Surface of the depreffed Water in the Air Box, then the Preffure of the included Air againft the upper Part of the Bellows, will be equal to that of a Body of Water a Foot deep, and as broad as the inner Surface of that Board. It will* therefore, be requifite, to add or take oft Weights, according to the different Depths of the Water in the Still, at different Pe¬ riods of the fame Diftiilation. The Bel¬ lows muft be proportionable to the Size of the Still, but need not be very large. Wherever the Stills are fixed in Ships, the Air may be conveyed to them from
the Bellows, either thro' a fmall leathern
«• ^
Pipe,, diftended with Spiral Coiles of Wyre, or thro* Bamboo Canes, or broad fmall wooden Pipes, like hollovv fifning Rods.
4*
9
Fresh Water at SEA,
4. When I firft diftiJLled in this venti¬ lating Way, in order to eftimate, what the Difference might be in the Quantity diftil- led, by that or the common Method, I tried both Ways, by receiving the diftilled Liquor into a Quarter of a Pint Glafs, eftimating the Times, by a Pendulum beating Seconds. Where I found, to my Surprife, that fometimes three times mote was diftilled by Ventilation than by the ufual Way : But finding Inequalities in the fmall Quantities thus diftilled, in or¬ der the more fully and afluredly to af- certain the true Proportion there was in the two Methods of diftilling, I put three Gallons of Water into the Still 5 and, when ic boiled, put on the Still-head, and fixed its Nofe to the Worm-tub Pipe 5 which Tub was full of cold Water. When it had diftilled for an Hour, the Receiver was inftantly taken away. And on meafuring the diftilled Water, found it to be two Quarts and 4^ cubick Inches by a Glafs di¬ vided into cubick Inches. And a Gallon containing 282 cubick or folid Inches, this Quantity of diftilled Water, which
was
•' - * ..
io To make Tlenty of
was 186 cubick Inches, is xVth Part of a Gallon. , : 1 ' -v
f. Then, filling the Still as full of Wa¬ ter as before, and when it began to boil, fixing the Head to the Still and Worm- tub, which was full of cold Water ; there was diftilled in an Hour, with conftantly blowing Showers of frefh Air up thro" the Hilling Liquors, five Quarts, lefs by feven cabick Inches, which is 3451 yths cubick Inches : that is, little lefs than the double of the Quantity that is diftilled in the ufual Way. In feveral other Diftillations of a Quart at a Time, I found the Quantity diftilled by Ventilation, to be more than the double of th3t in the ufual Way. So that the Quantity by Ventilation, may at a Medium be eftimated the double of the ufual Diftillation. It is the well known Property of moving Air, to carry along with it a confiderable Quantity of adjoin¬ ing Vapour, as alfo of falling Water to £arry much Air down along with it.
6. It is to be hoped therefore, that fo conftdcrablo an Increafe in the Quantity
diftilled,
Fresh Water ^ SEA. it
diflilled, will be of great Benefit to Na¬ vigation, as it may be done in lefs Time
and with lefs Fire.
1 *
• ' * I • 1 - : T ,
7. In the Account of Mr. Appleby & Procefs, for making Sea-water frefh, which is publifhed by Order of the Lords of the Admiralty in the Gazette of Jan, 22* 175*4, it is faid that a Still which contains 20 Gallons of Water will diftijl 60 Gal¬ lons in ten Hours with little more than one Bufhel of Coals; and therefore 120 Gallons in 20 Hours, with little more than two Bufhels of Coals. And by Ventila¬ tion 24,0 Gallons, or a Tun ; and 24 Gal¬ lons may be diflilled in twenty Hours, making an Allowance for the times of heating thofe Stills full of cold Water; and a Still fomething larger and wider, will ditiill a Tun in 24 Hours 5 which will more than fuffice for a fixty Gun Ship with 400 Men, whofe Provifion of Water for four Months is about no Tuns. And larger Ships may either have proportion- ably larger Stills, or elfe two of them. As for Merchant- Ships with few Men, a (mail Still will be fufficient.
8. Tm
iz To make Tlenty of
V /
l
8. The fecond fized Stills contain i© Gallons, and will produce 60 Gallons in 20 Hours, with half the above-mention¬ ed Fuel > and by Ventilation 120 Gallons.
9. The leaft Stills contain five Gallons, and will produce 32 Gallons in 20 Hours ^ and by Ventilation 6 4 Gallons in 20 Hours,
10. I have feen fame of thefe Stills at Me firs. . Steel and Stephens , over-againft Mercers- Chapel^ in Cheapjide , which have been made for this Purpofc* There are Holes in the Feet of the Iron Frame or Stove to skrew them down to the Deck. They were fixed at the Fore-caftle before the Mafl: in King Charles the Se¬ cond s time, when they thought they had difeovered the Way to diftill Sea-water, free from the noxious Spirit of Salt, and from the naufeous bittern Tafte. Or, if it be thought proper, one Part of the Ships Boiler may be made ufe of, by adapting a Still-head to it.
IT. Now
Fresh Water at SEA. 13
11. Now fuppofing a Still to contain Gallons, and that four Parts in five of it, viz. 20 Gallons are diftilled off: then,- in order to diltill a Tun , or 210 Gallons , the Still mud be emptied, cleanfed and refilled eleven times y and if the whole be done in 24 Hours, full 16 of thofc Hours will be taken up in diftilling at the rate of a Gallon in about four Minutes and half; and the remaining eight Hours of the 24, being divided into 11 equal Parts, they will be each near 44 Minutes to empty and cleanfe the Still, to refill it, and give the Sea-water a proper boiling diftilling Heat : whether this can be done in fo fhort a Time, muft be known by Experience, and ought therefore firft to
be tried at Land.
__ \ • -
, 12. Doftor Butler , in his lately pub- lifhed Method of procuring Frejh Water at Sea , propofes the pouring in more Sea¬ water into the Still, thro" a Funnel fixed in a fmali Hole in the Head or Upper-part of the Sti ll, when more than half the former Water is diftilled off; by which means the Water in the Still will Coon acquire a diftil¬ ling
14 7o make \ Plenty of
ling Heat; and this to be repeated fevcral times ; but then it will be requifite to add each time more Chalk, in fuch Propor¬ tion as fhall be found requifite. It will be well to try this Method in hopes there¬ by to increale the Quantity of Water that is diftilled. The Hole in the Head, or Upper-part of the Still, is to be flopped with a fmall Plate of Copper, fo fixed as
/
to turn to and fro over the Hole.
13. Doctor Butler ufed capital Soap Lees, in the Proportion of a Wine Quart to if Gallons of Sea- water, which fuffi- ced for four or five times repeated Pour^ ings in of more Sea- water into the Still* But as I have found that a fmall Quantity of Chalk has the fame good Effect, and is cheaper, and more eafily to be had, it is therefore preferable to Soap Lees.
14. When there is a Fire in the Cook- room, the Sea- water might be ready heated to put into the Still, without any addi¬ tional Expence of Fuel, in the following Manner, which I fhall here deferibe 5 tho* i think it probable that it will not be put
in
■/» ,
x
Fresh Water at SEA. if
in practice 5 yet, as farther Improvements may poffibly hereafter be made in it, and as it may be of ufe in fome Cafes, at Land at lead, I fliall here give an Account of it, viz.
if. About the Year 1718, Mr. Schme~ ton , a German Gentleman, got a Patent here for heating great Quantities of Wa¬ ter, with little Expence of Fuel, which he then {hewed me. Having fixed a fpiral Iron Worm-pipe, in fuch a Brick Stove or Chimney as Women heat their Irons in., thereby caufing the Water to run from a VefieJ, thro’ the Worm-pipe, fcveral Feet Length round, in the Fire. About 30 Years after I acquainted Mr. Cramond of Twick¬ enham with this, as hoping it might be of Benefit in diftilling Sea- water. Upon which he procured fuch a fpiral Iron W orm-pipe, which was about twenty Feet long, and fix-tenths Inch Diameter 5 the Diameter of the fpiral Coile was about fourteen Inches.
16 . This I fixed in a Brick Stove in my Garden, with its upper End fixed to a
Veffel,
16 To make Tlenty of
VefFel, which contained 4y Gallons of Wa* ten I found the Event of this firft Trial to be as follows, viz. When the Water run full Bore, at the rate of a Gallon in
17 Seconds, the Heat of the Water was found, by a mercurial Thermometer held in the Stream, at the lower End of the Pipe > to be 80 Degrees above the freezing Point* 180 Degrees being the Heat of boiling Water. When by means of a Turn-cock, a Gallon of Water was two Minutes in running, then the Heat was 140. At which Rate the 45 Gallons would be an Hour and half in running thro" the Iron- pipe? at which Rate 25 Gallons will run thro' in 50 Minutes, with fo confiderable a Degree of Heat 5 and if it was an Hour running, the Heat would approach ftill nearer to a boiling Heat, when fitft put into the Still, which would forward the Diftillation if wanted.
17. I pumped the heated Water up a- gain into the upper Vcflel 5 and thus con¬ tinued to circulate the heating Water, till its Heat was 160 Degrees in the upper Vefiel, viz, within 20 Degrees, or one- 4 , ninth
Fresh Water at SEA. ij
ninth of boiling, the Heat requifitc for plentiful Diftillation. I was in hopes that if the Water in the upper Veffel could have been brought to a due Degree of Heat* and a Still-head were fixed on it) with its cooling Worm-tub, then Water might have been diflilled in Ships, by having the Iron Worm-pipe fixed in the Chimney of the Cook-room : But' I found, that when the Heat of the Water in the upper Veffel was 160 Degrees, viz. within one-ninth of boiling $ then in running through the Iron Worm-pipe again, it was fo over¬ heated, as to expand in the Pipe, into an explofive Vapour, which hindered the run¬ ning of the Water. However I thought it not improper to give an Account of this Attempt, notwithftanding it failed. Not knowing whether this Method of heating Water, may not in fome Cafes, at Land at lead, be of ufe, thereby to fave, in fome degree, both Fuel and Time : Perhaps an Iron Worm-pipe of a larger Bore might do better.
1 8. Th e Wafte of Fuel will be lefs in proportion to the Quantity diftilled in
B large.
1 8 To make Plenty of
large, than in fmall Stills 5 and the wider the Still-head is, fo much the more Li- quor will be diftilled, and more with a Worm-tub than without it. The Worm- tub may be fo covered, as to prevent the flowing over of the Water by the Mo¬ tion of the Ship.
19. It is of great Importance to take care to keep all Parts of the Still dean* that there may be no Ruft or Verdigreafe in the Copper, which will occafion Vomit- fog.
20. If it be neceffapy, the better to clofe the Joining of the Still-head, it may be done with a Lute or Fafte made of a Mixture of powdered Chalk and Meal? wetted with Salt-water.
21. Now that feveral effe&ual Means are difcovered, to make diftilled Sea-water wholfome, and alfo to diftill it in much greater Quantity in the fame Still, in the fame Time, and with nearly the fame Quantity of Fuel ; it is rcafonable to be¬ lieve? that it will be of great Benefit to
4 Navi-
/
Fresh Water at SEA, ip
Navigation, not onJy in living much (tow¬ age room, for other important Purpofes > bat alfo in procuring frefh fwcet wholfomc Water, inftead of (linking putrid Water, hitherto lifed > which muft needs have a Tendency to promote that putrid Diftcm- per, the Scurvy. And if withal due Care be taken, to exchange for frefh Air the putrid clofe confined Air of Ships, which has occafioned the Death of Millions of Mankind > then Navigation will become remarkably more healthy, and with little more Danger to Health and Life, than at Land, except from Storms.
22. Now fuppofing, that in a fixty Gun Ship, the iio Tuns of Water, for four Months ufe, were diftilied at the Expence of three Bufhels of Coals to a Tun, this
*
would con fume nine Chaldrons of Coals $ And as a Chaldron of Coals weighs about a Tun and half 5 hence it appears that Coals will diftill about eight times their Quantity of Water* And the 1 10 Tuns of Water weighing (at the Rate of 2240 Pounds to the Tun) 138 Tuns; and the nine Chal¬ drons of Coals weighing thirteen Tuns and
B 2 half.
so To make 'Plenty of
half, that is 94 Tans and half lefs than the no Tuns of Store-water 5 and allowing twenty-four Tuns and half for the Still, Water-casks, and Coals, there will be 70 Tuns Weight of Stowage faved thereby for other Ufes. Or if fome Tuns of Store- water are carried by way of Precaution, which it will be advifable to do, efpecially at firft, till they can be allured, by repeat¬ ed Experience, what (Quantity can be de¬ pended upon by Diflillation 5 even then about half the Tannage will be faved, which will be a very material Advantage.
1
*
23. Tho5 when the diftilling Liquor runs from the Bottom of the Worm-pipe, thro" a long Pipe fixed to it, the Wafte by the ventilating rufhing Air, is not great when the Water in the Worm-tub is not hot ; yet the following Precaution, if needful, may be ufed, in diftilling by Ventilation, viz. to fix at the lower End of the Worm-pipe, by means of a wooden Fawcet, a fmall Cask for a Receiver 5 the Fawcet to enter the upper fide of the IJcad of the Cask, and in order to give a free Pailage for the great Quantity of ventila-
Fresh W a ter ^ SEA. 21
ing Air to pafs off, and withal at the fame time to prevent the e heaping of much moift Vapour with it, it will be proper to fix at the Bung-hole a long upright Pipe of Wood, or of any Metal. I ufed a Gun- barrel four Feet and a half long ; through which fome fmall Degree of moift Vapour efcaped 5 as appeared by the Dampnefs of a Piece of Paper, fixed at a little Didance above the Mouth of the Gun -barrel. This ' Vapour became vifible, and much increafed, when the Water in the Worm-tub was very hot 5 at which Time, lefs is diddled into the Cask-receiver; then alfo there is more Danger of the Spirit of Salt arifing. And it was obfervable, that the Water in the Worm-pipe VefTel heated much fooncr by Ventilation, than in the common Way of diddling. For which Reafon that Wa¬ ter ought to be changed fo much the of- tener, which can eafdy be done at Sea. The Cocks alfo at the Side of the Worm- tub ought to be large, in order to let the hot Water off the fader.
24. But tho' the Water in the Worm- tub was fooner heatyd by Ventilation, be-
B ? caufe
21 To make Plenty of
caufc a double Quantity of hot Steam paf- fed thro’ it, more than pafied thro’ it in equal Times in the common Way of di- falling 5 yet in the ufual Way of Dift illa¬ tion the Liquor in the Still is hotter, with equal Fire, as is evident by its aptnefs to boil over thro’ the Worm-pipe 5 whereas in the ventilating Way it did not boil over, notwithstanding a very hot Fire was pur^ pofely made for a Trial. The continual Streams of afcending frefh Air, not only in feme Degree abating the Heat of the Waters but alfo inceffantly carrying off the more rarefied Particles of the Water, which, when expanded into a repelling State, do thereby caufe the overflowing Ebullition of the Water. On which Ac-* count it is probable, that lefs Spirit of Salt is formed and raifed by Ventilation than
v ithout it. As alfo on account of the
# * —
frefh Air afcending, not from the Bot¬ tom of the Still, where is the greatefl: Plenty of Salt, efpecially towards the lat¬ ter End of each Diflillation 5 but about three Inches from the Bottom, viz. prin¬ cipally from the many Holes at the Sur¬ face of the Air^box.
And
Iresh Water at SEA. 23
2y. And whereas the Quantity raifed from the Still, and diftilled into the Cask- receiver, cannot be feen 5 the proper Quan¬ tity to be diftilled in each Diftillation, may with great Accuracy be known, by having a well clofed Pewter Bottle of the Size of about half a Pint, with a Brafs Wyre as big as a Goofe Quill fixed to it, the Wyre to pafs thro’ the Receiver-cask, near the Bung- hole, which the floating Pewter Bottle will raife up, till the Marks on the Wyre appear juft above the Cask. I made ufe of a Glafs Viol for this Pur- pofe. This Wyre will rife and fall freely, notwithftanding the Morion of the Ship, if it paffes not only thro’ the Wood of the Cask, but alfo thro' a metaline Pipe two or three Inches long, fixed in that Hole. And it will be known by the fimmering or boiling Noife of the Water in the Still, whether it is hot enough to diftill 5 for the running of the Water into the Receiver- cask cannot be feen.
26. As it might be fufpefted, that more Spirit of Salt would be raifed, and diftilled
B 4 over
14 To make Tlenty of
over in the ventilating Way, than without it; having procured 18 Gallons of Sea¬ water by the Margate Hoy, which was taken up at feme Diftance from the Shore, I put three Gallons of this Sea-water,, as foon as I had received it, into the Still 5 and when it began to diftill, Air was blown up thro' it. For fome Time, | as is ufual, in the Diftillation of Sea-water ; no Spi^ rit of Sait arofe ; but after diftilling fome Time longer, there were very weak whitifh Clouds, with Drops of Solution of Silver in Aqua-fortis, as in the common Way of diftilling. Hence we fee, that Ventilation does not increafe the Quantity of Salt, but rather probably fomewhat decreafes it> for the Reafons above given, N° 24.
27. I distilled three Gallons of Sea¬ water, which had flunk and became fweet again ; when about ten Quarts of it had been diftiiled off, then there began to be very weak whitifh Clouds with Solution of Silver, but none with Solution of Mercu¬ ry; which fhows the Water to be hitherto good, agreeably to what I formerly had found to be the good Effeft of diftilling 3 Sea-
Fresh Water at SEA, 2f
Sea-water, which had putrified, and be¬ come fweet again ; of which I publifhed an Account in the Year 1739. But when I continued the Diftillation on, a quarter of an Hour longer, viz. till there was but a Pint of Water remaining in the Still, and the Salts were incrufted on its Sides, up near three Inches from the Bottom, and lay in Heaps at the Bottom of the Still, then the diftilled Liquor had whitifh Clouds in it, with the Solution of Mercury in Aqua-fortis. From this Diftillation we fee, that Putrefa&ion, by diflolving the bittern Salt and Bitumen, into very minute Parts, qualified them to combine with the more fixed common Salt, fo a» to detain them from riftng in Diftillation.
28. I distilled three Gallons of Sea¬ water, with the Proportion of fix Ounces of Mr. Appleby s Lapis Infernalis, and fix Ounces of calcined Bones to 20 Gallons of Sea* water, as he directs. This Water la¬ thered well with Soap, and boiled Peas well.
29. I distilled alfo fbme Sea-water With half an Ounce of Stone Lime to a
Gallon,
z6 To make Plenty of
Gallon, from the Clee Hills in Hereford -
t
which having been preferved ten Months in a Firkin, had flacked to dry Powder. This diftilled Water did alfo lather well with Soap, and boiled Peas well > which proves that the Lime, which is a fixed Body, does not diftill over with the Water. Since I made this Diftilla- tion, General Oglethorpe informed me, that his Father, Sir Theophilus , told him, that Lime was one of the Ingredients, of what he and the reft of the Patentees, in Charles the Second’s time, called the Ce¬ ment, with which they made diftilled Sea¬ water wholfome.
30. I distilled alfo fotne Sea-water with the like Proportion of powdered Chalk, which boiled Peas well, and was better tailed than the Waters diftilled with Lapis Infernalis or Lime. 1 diftilled alfo ibme Sea-water with an Ounce of Chalk - to a Gallon, but found no Difference in the Tafte of this, and that which had but half an Ounce of Chalk to a Gallon : So that half an Ounce of Chalk to a Gallon of Water will be fufficient 3 but, where
the
Fresh Water ^ SEA. 27
the Sea-water is falter, or more bitumi¬ nous, more Chalk may be added if need¬ ful.
31. Dr. Aljlon of Edinburgh , in the Preface to the Second Edition of his Dil- fertation on Quick-lime and Lime-water, fays, that <c the like EfFed was found in cc diftilling Sea-water with Lime, that it ie neither precipitated a Solution of Silver “ in Aqua-fortis, nor a Solution of cor- u rofive Sublimate in Water, nor did it <c form a Pellicle of various Colours on “ its Surface, as did the Water diftilled
by Mr. Appleby % Procefs.” And I find. Page 35 of my Book on this Subjed, that Lime of Oyfter-fhells had the fame good Effed, but required two Diftillations 5 I might then ufe too fmall a Quantity of that Lime. Hence it is probable, that the Chalk, the Lime, -the Lime in the Lapis Iilfernalis, and the Lime in Dr. Butlers Soap-lees, feize on and fix not only the bittern Salt, but alfo the Bitumen of the Sea-water, as we learn from the like Ef¬ fed in the Purification of the Salt of Hartfi horn* That the faline Spirit arifes chiefly
from
2% To make Plenty of
/ *
from the bittern Salt, and not from the more perfed Sea-falt, is probable from hence, w. when I diftilled three Gallons of common Water, made as lalt as Sea-' water with common Salt > no Spirit of Salt arofe, even tho* the Diftillation was carried fo far as to leave the Salt, tho* very damp, to lie in Heaps, and it was in- crufted on the Sides of the Still, for about three Inches from the Bottom.
32. It is a confiderable further Advan¬ tage, that Water thus diftilled by Ventila¬ tion, being thereby repleat and freshened with Air, has for prefent Ufe a more a- grceable Tafte, than Water diftilled with¬ out Ventilation, which requires the (land¬ ing a longer Time to have its more dis¬ agreeable aduft Tafte go off. And as the volatile Oil of Pepper-mint does rife on the Wings of the ventilating Air during the Diftillation 5 fo alfo may that Part of the Bitumen, which is volatilized by Heat 5 as alfo the volatile urinous Salts of the Sea water, which arifes from animal Sub- ftances, be fublimcd in the fame Manner.
33- lT
Fresh Water at SEA. 29
33. It was obfervable, that the Water diftilled faft, even tho’ the Water in the Still was below ‘the Surface of the Tin Ait-box, thro’ which the grcateft Part of the afcending Shower of Air rufhed. Hence the ventilating Air, in afcending among the Vapours, carries them off faft. Hence it is to be fufpected, that this Method of Ventilation will not do well for ftmple Waters, or fermented vinous Spirits ? be- caufe they being very volatile, much of them may be carried off in Wafte.
34. It was obfervable, that in thefe Dif-
tillations of Sea-water, no whitifh Clouds appeared on dropping in Solution of cor- rofive Mercury, not even when con fid er- ably more than four Parts in five of the Water had been diftilled over. And it was the fame with the Mixture of Lapis Infer- nalis, Lime, and Chalk 5 whence it is pro¬ bable, that the Lime and Chalk feize on and fix the more volatile bittern Salt, as does alfo the Lime in the Lapis Infernalis. And it is well known, that Sugar, that fweet Salt, cannot be made without Lime, on which, as its Centre of Union, it fixes and granulates. 3f, And
3°
To make Plenty of
jjT. And whereas with a Solution of Silver in Aquafortis, which was much weakened and diluted with Water, there appeared a faint Degree of whitifh Cloud, in all the above-mentioned Diftillations, tho* not with the ftronger Solution of Mercurv till the Diftillation was carried
«r
on, much beyond four Parts in five of the Water in the Still ; when both Solu¬ tions caufed remarkably white Clouds, efpecially the Solution of Mercury $ which
A
indicates the Quantity of the Spirit of Salt which was raifed during the former part of the Diftillation to be exceeding fmali, fince it could not feize on, nor difengage the Aqua-fortis from the ftronger Solution of Mercury, tho' it did in a very fmali Degree in the weak Solution of Silver, fo as to let loofc a very little of the Sil¬ ver, which thereby caufed the faint Clouds, When a Drop of the Solution of Mercury was dropped into the diftilled Water, af¬ ter a Drop of the Solution of Silver, it re for bed the Silver Cloud, and made the Water clear, by means of the great Pro¬ portion of add Aqua-fortis that was in it.
36. Now
Fresh Water at SEA. 31
36. Now in order to make feme Efti- mate of the very fmail Quantity of Spirit of Salt in thefe fevcral diftilled Waters, l dropped a Drop of the Solution of Silver into an Ounce, or 480 Grains of pure
Rain Water, which gave no Clouds ; but
✓
on dropping in a Drop of Sea-water, which weighed a Grain, the white Clouds were ftrong. And fince Sea-water can diflfolve nine times more Salt than it has in it 5 therefore, fuppofing the Drop to be fo fully impregnated with Salt, then the Salt would be the 480th Part of the Ounce of Water. But as there is nine times lefs Salt, therefore the Proportion of the Quantity of Spirit of Salt will be but the 4320th Part. And how much lefs muft be the Proportion of Salt in thefe di¬ ftilled Waters, which is not fufficient to make a fenfible Impreffion on Solution of Mercury, and but a faint one on much di¬ luted Solution of Silver. Such diftilled Sea-water will not therefore, probably be unwholfome 5 almoft all Spring-waters have fome Degree of Salt in them : But if there were more of the Spirit of Salt, a
very
32 To make cPlenty of
very final l Quantity of Pot-afh, or Pearl- afhes, or Salt of Tartar, combined with it, will turn it into common Salt, the Quan¬ tity of which would be extremly iittle.
3 7. It may be well to be provided in Ships with fome Silver diffolved in Aqua¬ fortis, mixed with pure Rain- water, or di¬ ddled frefh Water, in the Proportion of fixty Drops to an Ounce of the Water* tho' it is probable, it may feldom be want¬ ed, unlefs in fome doubtful Cafes, when the Tafte may not be accurate enough to perceive, whether there be any Spirit of Salt in the diddled Water.
38. Since double the ufual Quantity of Vapour may by Way of Ventilation be carried off, common Salt may thus be made much lboner, cheaper, and better* becaufe as there is much lefs Fire ufed * fo proportionably, lefs of the fine acid Spirit of the Salt, in which its Virtue con- fids, will be evaporated away : For it is well known, that the Salt is bed which has undergone the lead Adion of Fire in making,
wf
39. This
Fresh Water at SEA, 33
39. This more fpeedy Method of eva¬ porating will alfo be ufeful, in makin many other Evaporations 5 as in makin Pot-afh, &c.
40. But fome are apprehenfive, that this great Improvement in Diddling, may be of ill Confcquence in making thole de« ftruftive Spirits cheaper, which are already but too cheap. Had not the Improvement been of great Benefit to Mankind in many other Refpects, I fhould have been far, very far, from endeavouring after it, or difco- vering it. But fhould the Event be to
1
make thofe Spirits cheaper, and confer quently, by fpreading farther, more de~ ftruftive, the confequence of that will be, that the increafed raging Devaluation will the fooner necedarily roufe the Nations to put a Stop to what mud be done here¬ after ; for if the Ravages continue increaf- ing, as they have done for flxty Years pad, the human Species mud needs not only be greatly dcbafed, but even in great meafure diminifhed and deftroyed. And yet none of the Nations, whofe very Vi-
C tals
fjq Qq
34 To make Plenty of
tals arc thereby confirming and deftroying, endeavour to put any Stop to it, except the Heads of the native Indians in North - America , who have long repeatedly in- treated the Englifh to fell them no Rumj which is as effectually extirpating of them, as the Hornet did the unfubdued remaind¬ er of the Canaanites .
41. If Mankind, inftead of receiving and entertaining this Peft with almoft uni¬ ter fa 1 Applaufe and Approbation, could prevail with themfelves to be in earn eft to ufe Means to deliver themfelves from it 5 then much might be done towards it, by lowering and weakening all kind of fermented diiiillcd Spirits with Water, to a falutarv Degree, as is now pradlifed in our Plantations in America , in making Punch fo weak, as not to be hurtful j which, when it was much ftronger, was well known to deftroy Multitudes. And where the like humane, wife, and lauda¬ ble PraClice has been ufed in Ships, it has had the fame happy falutary Effedt.
42. What?
Jre§h WaIer at SEA.
Bf
42. What Neceflity dr even Tempta--
. /
tion can there be to be averfe to the mak¬ ing them wholfome, inftead of being ve¬ nomous and deftru&ive ? and that not only of the Lives, but even of the Morals of Mankind. How much therefore does it behove all, who have any Concern for the Honour and Dignity of their own kindred Species, any Indignation at its being thus debafed and difgraced* any Bow¬ els of Pity for the vaft Multitudes, not lefs than a Million, that are yearly deftroyed all over the World, by this moral as well * as natural, and therefore word of all Evils that ever befel unhappy Man 5 to ufe their iitmoft Endeavours to deliver Mankind from this Peft £ But notwithftanding this aftonifhing Ravage and Deftru&ion of the
human Species, yet the unhappy unrelent¬ ing Nations of the World, feem as uncon¬ cerned about it, as if only fo many Thou- fands, nay, Millions of CaterpiUers or Lo- eufts were deftroyed thereby. Was there ever a more important Occafion to roufe the Indignation of Mankind ? Can we be calm and unejifturbed, when this mighty
C 2 Deftroyer
36 To make Tlenty , &c.
JDeftroyer rears up its invenomed Head every where ? The moft zealous Advocates for Drams, even the unhappy befotted Dramifts themfelves, the . prolonging of whofe Lives, and whofe real Welfare both here and hereafter, is hereby fincerely in¬ tended, cannot find fault with this well-
wi*-
meant Remonftrance, in Defence of them, and of all Mankind, againft this mighty Dcftroyer, from one who has long been labouring, and that not without Succefs, in finding Means to preferve Multitudes of Lives, by various W ays.
An
r
[ 37 3
An Account of the great Benefit of Ventilators in many Injlances , in preferving the Health and Lives of People , in Slave and other Transport Ships.
43.IT is to be hoped that the feveral 1 Means here propofed for having
i
frefh and fweet Water at Sea, will be of great Benefit in preferving the Health and Lives of Multitudes of that valuable and ufeful Part of Mankind, thofe who oc¬ cupy their Bufinefs in great Waters 5 whofe Welfare I have long had at heart, and en¬ deavoured to promote by various Ways 5 efpecially by finding Means to procure them frefh falutary Air, inftead of the noxious, putrid, clofe confined peftilential Air, which has deftroyed Millions of Man¬ kind in Ships. And it is to be hoped that by diligent Refear'ches, farther and farther ufeful Difcoveries will hereafter be made for the Benefit of Navigation,
44. The following, as they are ftrong Proofs of the great Benefit and Ufefulnefs
C 3 of
|8 Benefit 0/ Ventilators
of Ventilators in Ships, fo they alfo fully prove that they can moft commodioufly be fixed arid worked in them, in contra¬ diction to the vulgar, falfe, and grpund- lefs Notion, that they take up too much room, and are incommodious, and in a
. i 1 i
manner impracticable to be worked, where¬ as the Men are eager to work them 5 and many more Perfons can be with Safety to their Health and Lives in a ventilated, than in an unventilated Ship j which fully obviates the Objection as to the Room they take up. In new and important Re-* fearches, the likeliefi Way to fucceed, is to purfue a Thought not only by imper¬ fect and fallacious Reafonings, but when the Nature of the Thing requires it, with a proper Series of Trials and Experiments* Thus in the prefent Cafe, the principal Caufe of the Sicknefs in Ships, is the noxious putrid Air 5 the obvious Remedy is the exchanging that foul Air for frefh, by effectual Means, which are feldom dis¬ covered by dwelling only on Objections, but are ufuaily the Reward of repeated diligent, experimental Refearches. Nei¬ ther are we to be difeouraged in thefe
in SHIPS. 29
*
our Purfuits by fome Difappointments, for I have frequently found that they lead to the Thing fought for : And by the like Clue of Reafoning and Experimenting, there is the greateft Probability that we fhall fucceed in another very important Refearch, viz. the preferving touch longer from Decay the Timbers of Ships laid up in ordinary in Harbour : For as we arc allured by daily Experience, that the De¬ cay is wholly owing to damp, clofe con¬ fined putrid corroding Air 5 fo the only Remedy for this Evil, is the frequently changing the Air among the Timbers, by plentiful Ventilations 7 which we find by happy Experience, can be effe£ted to fuch a Degree, as give reafonabie Hopes, enough to encourage our fartherTrials andRefcarchcs.
* i
\ i
4y. Captain Tho?nfon of the Succefs Frigate, in his Letter to me dated Lon¬ don , Sept . 2y, 1749, lays, tc That during u the Ventilation, the Lower-deck Hatches ic were commonly kept clofe fhut$ by <c which means the Air was drawn down <c into the Hold, from between Decks, , thro' the Seams of the Ceiling, along the
C 4 Timbers
/
4<o Benefit ofi Ventilators
€c Timbers of the Ship 5 by which means we found the foul Air foon drawn
c£ off from between Decks. Our Rule e£ for ventilating was for half an Hour
“ every four Hours $ but when the Ven-
dialing was fometimes neglected for c£ eight Hours together, then we could
€c perceive, efpecially in hot Weather, a cc very fenfible Difference by that fhort “ Ncglc£t of it $ for it would then take a €£ longer Time to draw off the foul Air. €c Our general Rule was, to work the u Ventilators till we found the Air from them fweet. We all agreed that they 4£ were of great Service 5 the Men being fo fenfible of the Benefit of them, that “ they required no driving to work that c< which they received fo much Benefit by. c£ We found this good Effeft from Vcn- ic tilation, that tho’ there were near 200 ec Men on board, for almoft a Year, yet I landed them all well in Georgia , not- lt withfianding they were preffed Men, H and delivered me out of Goals, with Diftempers upon them. This is what 6t I believe but few Tranfports, or any other Ships, can brag of; nor did I H ever meet the like Good-luck before ;
which
.3
in SHIPS. 41
“ which, next to Providence, I impute to « the Benefit received by the Ventilators. €C It is to be remarked, that we who lay <c wind-bound, for four Months, with <c our Expedition Fleet, which foon after
invaded France , were very healthy all u the time, when they were very fickly in “ all the Ships of that Expedition.
46. c‘ This certainly occafioned all kind cc of Grain Provifions to keep better and cc longer from Weevels, than otherwife
they would have done ; and other Kinds <c of Provifions received Benefit from the cc Coolnefs and Erefhnefs in the Air of <c the Ship, which was caufed by Ventila- c non.
4 7. Mr. Cramond alfo informs me, that he found the good EfFed of Ventila¬ tors on board a Slave-Ship of his with 392 Slaves, twelve of which were taken on board, juft before they failed from Gui¬ nea, ill of a Flux, which twelve all died ; but the reft, with all the Europeans in the Ship, arrived well at Buenos Ayres .
The
42 Benefit of Ventilators
%
The following is a Letter to me from Captain ELLIS, viz.
“ Sir,
*
48. Ct r^OULD any thing increafe the u Pleafure I have in a literary Inter- courfe with you, it would be to find that cc it anfwered your End in promoting the “ public Good. The Vis-inerti£ of Man- <c kind is not the only Difficulty you have £t had to encounter, but their Ignorance <£ and Prejudices, which are almoft infu- €( perable. It is to your Perfeverance and sc Refolution, that the little Progrefs you c< have made is due : Indeed I ought not c£ to fay little 5 for it is a great Step to *c have found the few that have Hearts c< good enough to reliffi your Plan, and Heads fufficiently clear to difeern the cc mo ft effettual Method of advancing it.
It does Honour to thofe noble and other “ worthy Perfonages that join you in A fts of fuch extenfive Humanity, as the In- €£ troduftion of Ventilators to Hofpitals, Prifons, Ships of War and Tranfporr, u as they mud neccflarily render the 5C Miferies of the firft more fupportable,
* .. and
in SHIPS. 45
^ and the clofe and conftant Confinement u of the others lefs prejudicial and fatal to “ their Health and Life. It is tQ be la- €t mented that they are not more generally “ made ufe of $ for, notwithftanding their cc Advantage is apparent and incontestable, <c it is fcarce credible how few are to be cc found among the vaft Number of Ships €e daily employed in carrying Pafiengers, “ Slaves, Cattle, and other perifhable Com- “ modifies. Thofe of your Invention, u which I had, were of lingular Service to “ us 5 they kept the Infide of the Ship cool, cc fweet, dry, and healthy : The Number .4< of Slaves I buried was only fix, and not “ one white Man of our Crew, (which 44 was thirty-four) during a Voyage of iy u Months 5 an Inftance very uncommon, <€ The 340 Negroes were very fenfible of u the Benefits of a eonftant Ventilation, *c and were always difpleafed when it was “ omitted : Even the Exercife had Advan- te tages not to be defpifed among People “ fo much confined. I muft not, however, forget that Ventilation alone is infuffi- cient to keep Diforders out of Ships > ff for often Infections are brought aboard
“ by
cc
cz
Benefd of Ventilators
<c by the Slaves, or others 5 and frequently €C Difeafes are produced by feeding on bad u or decayed Food, but oftener hill by Infobriety ; for I have ever remarked. <c that the immoderate Ufe of fpirituous u Liquors in warm Climates, is more per- nicious and fatal even than the Malig- cc nancy of the Air itfelf. In cold Coun¬ tries too, where I have had Experience, thofe Sailors, or others, who accuftom- €c ed themfelves to hard drinking, efpeci- u ally of Drams, had the Scurvy in a ter- Q rible Degree ; whereas thofe who were cc temperate or fober, either efcaped it en- sc tirely, or had it but moderately. The €C Effedts of Drunkennefs was ftill more lc difcernable among the Indians adjoining our Settlements in Hudfori s-Bay, who are a feeble, diminutive, chilly, indo¬ lent Set of People. On the contrary, thofe who come from the inland Parts “ (who ure unufed to drink Brandy) are gc brave, active, robuft, and induftrious. €c The fame Difference is obfervable in the “ Africans , and perhaps among the Inha-
<c bitants of moft other Nations, did we at-
#
<£ rend to it. It was to the unufual Sobri-
V «y
cc
cc
cc
in SHIPS, 45*
u ety of my Crew, that I afcribed, in fome cc meafure, their uncommon Healthinefs >
for Sailors breathe a purer Air, and en- cc joy more Exercife and Liberty, than <c Paffengers or Slaves? wherefore their <c Ailments are owing to bad ordifordcr- “ ly Living, as well as to unwholfome “ Ain
<c Could I but fee the immoderate Ufe <c of fpirituous Liquors lefs general, and cc the Benefits of Ventilators more known <c and experienced, I might then hope to
“ fee Mankind better and happier, I am*
«
“SIR,
iC Teur mojl oledlens Servant?
Briftol, Dec.
26,1753. HENRY ELL IS"
49. And, by the like good Condud* in his next Voyage in the Year 1 755*, not one of 312 Slaves died? and all his 36 Sailors arrived alive and well at BrifloL
yo. And the Earl of Halifax has often informed me of the great Benefit they found by the Ufe of Ventilators, in feve~
ral
\
4# Benefit of Ventilators
ral Nova Scotia Tranfport-Ships* twelve to one more have been found to die in unventilated than in ventilated Ships* It is indeed a felf-evident Thing, that the changing the foul Air frequently in Ships, in which there are many Perfons, will be a means of keeping them in better Health than not doing it 5 which makes it the more aftonilhing that effeflual Propofals to remedy fo great an Evil, fhould be re- eeived with fo much Coldnefs and Indife ference by Mankind* They little confidcr that it is the high Degree of Putrefa&ion (that moft fufatile Difiblvent in Nature) which a foul Air acquires in long ftagna- ting, which gives it that peflilential Qua- lity, which catties what is called the Goal- Diftemper, And a very fmall Quantity* or even Vapour of this highly attenuated Venom, like the Infedion or Inoculation for the Small-pox, foon fpreads its deadly Infeftion, Ought not Men therefore, from the common natural Principle of Self-Prefervation, to life their utmoft En- deavours to ihun this peftiient Deftroyer* by which Millions of Mankind have pe- rifhed in Ships !
An
1 *
L 4 f )
An Account of fane "Try ah to cure the ill Tafte of Milk, which is oc~ cafioned by the Food of Cows, ei¬ ther from Turnips , Cabbages , or autumnal Leaves , 8c c. Alfo to Jweeten Stinking-water, 8cc.
yi. ^ | ’^HIS Method of blowing Show- JL crs of Air up thro5 Liquors, will be of confiderable Ufe in feveral other RefpeCts, as well as in Diftillation, as ap¬ pears by the following Trials, viz.
52. I have been informed that it is a common Practice, to cure the ill Tafte of Cream from the Food of Cows, by fetting it in broad Pans over hot Embers or Char¬ coal, and continually flirting it, till Raid¬ ing hot, and till cool again : But when I attempted to do this much fooner, and more effectually, by blowing Showers of Air up thro5 it; I foon found it to be im¬ practicable, by reafon of its very great De¬ gree of frothing up. The ill Tafte muft therefore be got out of the Milk, before it
is
1
4 8 III tafted
Is fct for Cream ; which I have been told, has been pra&ifed, and that with fome be¬ nefit, by giving the Milk a fcalding Heat, without flirting it.
53. May 22.I ventilated fome ill tafted, new unheated Milk of a Cow which was purpofely fed with Crow Garlick mixed with cut Grafs. After i f Minutes Venti¬ lation the Tafte was a little mended 5 in half an Hour's blowing it was fomething better. At the Hour's end it had the fame Tafte, but was fcnfibly better than the un¬ ventilated Milk. I was difappointed of an Opportunity to repeat the Experiment with Crow Garlick Milk, with a fcalding Heat • It would then probably have been foon perfeftly cured 5 as it is reafonable to be¬ lieve from the Event of the following Ex- periments, viz.
54. Auguft 23, four Quarts of ill tafted new Milk, from a Cow which had fed eighty -four Flours on Cabbage Leaves on- jy, and drank during that Time very little Water 5 were put into a leaden Veftel, eight Inches in Diameter, and thirty Inches
3 deep.
*
Mi l i£ to cure.
thes deep. The leaden Veflel was heated in a large Boiler, and fet into a Veflel of hot Water; thereby to give the Milk a fcalding Heat, and alfo keep it hot. In ten Minutes Ventilation it was perfe&ly cured of its ill Tafte 5 and after handing twenty-four Hours in a broad Pan? there Was a thick Scum which was half Cream and half Butter, free from any ill Tafte 5 the skimmed Milk was not fheer or thin ; So here is a Method to make good Butter from ill tailed Milk.
yy. The Froth of the Milk was fo great* by reafon of a too brisk Ventilation, as to make it froth over the Veflel, which was thirty Inches deep 5 if it had not been kept down, by coiiftantly lading and break¬ ing the very large Bubbles of Froth. But when the Ventilation is more gentle, the Froth has rifen but three Inches from fix Quarts of Milk, which was nine Inches deep. The Cabbage Milk was but fix Inches deep. I repeated the like Operation the fame Day, with the Evening Milk of the fame Cow 5 but giving it only a Heat, that Tcould bear my Fingers in, for a little
D Time*
50 111 tafled
Time $ with this Degree of Hear, after forty-five Minutes Ventilation, the Milk (tho* much better tafted) yet was not fo compleatly cured, as the former Milk. Hence we fee, how neceflary Heat is, to volatilize the rancid Oyl (which gives the ill Talk) to fuch a Degree as to caufe it to fiy off by Ventilation.
f6. It was obferved that what was milked from this Cow a Week after (he had done eating the Cabbage, had an ill Take.
57. I have not as yet had an Opportu¬ nity, to try to cure, in the fame Manner, the ill Tafte of Milk, which is occafioned by Cows feeding on autumnal Leaves, or Turnips, they having probably eaten this Autumn, the fewer Leaves, on account of the Plenty of Grafs, occafioned by much Rain ; which has alfo hitherto pre¬ vented Turnips from being rancid, which are obferved to be mod fo, when they (hoot out in the Spring. As Opportuni¬ ties offer I purpofc to make Trials, which 1 conclude others will alfo do, which will
probably
#
Milk to cure. y 1
probably be attended with the fame good Effects as that on the Cabbage Milk.
5 8. Bur tho’ the ill Tafte of Milk from feeding on Cabbage Leaves, was thus ef¬ fectually cured by volatilizing with Heat, and diffipating by Ventilation the rancid Oil; yet the bitter Tafte of a ftrong In- fufton of Chamomel Flowers in fix Quarts of Water, was not fenfibly abated by an Hour’s Ventilation of it, while fealding hot.
f9. I am informed that, in cDevonjbirey they fet the Pans of Milk on Trivets, making Fires under them, to give the Milk, gently and gradually a fealding, but not a boiling Heat, which would difturb the riling Cream 5 and then fet it on the Floor in the Milk-houfe to cool, where in twelve Hours it has a thick Scum, partly Butter and partly Cream : The skimmed Milk is very thin and fheer ; and the Cream in great Plenty and delicious, except it gets a fmoky Tafte, which it is apt to do > and which might probably be prevented, by having a Range of as many Stoves, as
D 2 there
III taftsd
there are Bans of Milk to be nfcd at one
V ' ~ " - *
Time ; all to be warmed by one Fire, ei? ther at one end, or the middle of the Flue
„ ■ • " -V
or Funnel in the Brick-work, which con- veys the Smoke and Heat under the Stoves, And as the Pans neareft to the Fire will
y . *
fooneft have their due Heat, on their Re¬ moval to bring the fartheft and cooleft Pans neareft the Fire $ and inftantly cover¬ ing the uncovered Stoves with proper Co¬ vers to prevent the Heat and Smoke from coming out 5 by this Means the Milk would all be foon heated, with any kind of Fuel, and th$t with much lefs in Quan¬ tity than in the common Way.
60. And the more effectually to pre¬ vent the Smoke from coming at the Milk, it may be well tp have the broad outer Rim of the Pans turned perpendicularly downwards, three or four Inches, that it may enter deep into a circular Groove of Sand 5 and if it fhall be needful the Sand may be wetted in order the more effedu- ally to prevent the Paffagc of the Smoke : 1 thought of this Method about fifty Years fmee on rafting the fmoky Butter in Se-
merfetftnre ,
Milk to cure. 53
merfetjhire . By the fame Means the Poor might fave much Fuel in bqiling the Pot, cfpecially in Summer, when a Fire is want- ed only for boiling the Pol
6 1. Whpn any Pans are to be removed from the Stoves, the A fcent of the Smoke thro* the uncovered Stove, may be pre¬ vented by firft clofing the Flue near the Fire, by an Iron Slidingrfhutter or Re? gifter.
6 2. Milk might thus moft commodi- oufly be heated to a Raiding Heat with little Fuel, fit for Ventilation, in a Veffel of a proper Depth, fet in the fame Man¬ ner as the Pans in a Stove, to fecure it from Smoke, with Bellows fixed properly pear it: (fee Fig. 3.) By this Means there would be little Trouble or Expence in curing ill tafted Milk by Ventilation.
63. May 14th, meerly to fee what the Event would be, a Gallon of new Milk, juft from the Cow was ventilated, for an Hour and half, which produced fix Ounces of Butter? and tho' it was ventilated half
an
54 /// tafled
an Horn* longer, yet no more Butter Was made 5 it was whitifh, wanting both the Colour and Tafte of good frefh Butter.
64. I am credibly informed, that in the Places famous for making the beft frefh Winter Butter, they fet the Pot of Cream in warm Water, fo long as till it has ac¬ quired that fmall Degree of Sournefs, which it very foon has in warm Summer Weather, which gives it its agreeable Plavour. And in order to give it Colour, they grate a well coloured Carrot into a little Milk, which as foon as Pained, is ftrained from the Carrot thro" a Sive, and then mixed with the Cream.
6y. It is found by Experience, that the Quantity of Cream is increafed, by putting into the Milk a little warm Water in Win¬ ter, and cold in Summer 5 which being thereby, in fome Degree thinned, the Cream is thereby more eafily difintangled, fo as more freely to afeend to the Surface of the Milk.
Milk to cure .
Jf
66. I ventilated three Gallons of ft inking Jeffop$-well purging Water. On firft blowing, the Smell of the afcending Vapour was very offenfive, which Often- fivenefs abated much in five Minutes : In eleven Minutes the Smell was much bet¬ ter: In twenty Minutes the Water feemed fweet both in Smell andTafte; and not fweeter at the End of forty-five Minutes* fifteen or twenty Minutes will probably fuffice. '
67. July 20th three Gallons of (linking Sea-water were ventilated; in five Minutes
lu
it was much fweetened, and no ill Smell in the afcending Air, tho" at firft: it was very offenfive : At the End of ten Minutes it had a fmall Degree of ill Tafte; after twenty Minutes no ill Tafte or Smell, It frothed near a Foot high during Part of the Ventilation ; this from the Bitu¬ men, &c.
68. Some Sea-water which was made to (link with Flefh and Ifinglafs being put into it, was not made perfedly fweet, not
even
$6 111 tajled
even by a ventilated Diflilladon, and ail Hour's more Ventilation after it was di~ flilled 5 fo that Putrefa&ion with ‘animal Subftances, is not ealtly compleatly cured by Ventilation.
69. When the Water was 2f Inches deep in the leaden Veffel, no Air could be blown up thro' it by the Force of the Bellows. But at 18 Inches Depth, the Air could freely be blown up in Showers thro' the Water 5 when therefore it is requifite to blow up thro* great Depths of Water, the Bellows may be worked with a Lever* as Smiths Bellows arg worked.
70. As it is found by Experience, that the Milk and Batter of Cows, which drink (linking Water, has a very bad Tafle, this plainly (hows that the Water retains its putrid Quality when mixed with the Blood 5 whence it is much to be fufpefted, that the (linking Water which is drank in Ships, by retaining its putrid Quality, even when mixed with the Blood, may thereby promote that pu-
2 trid
Milk to dire.
trid Diftemper the Scurvy, as well as fome other Diftempers. And much more does the putrid clofe Air in Ships, which is mixed with the Blood from the Lungs* promote putrid and other Diforders : By the fame Means alfo, peftilential Infec¬ tions are taken in : For as the falutary Properties of good Air, are conveyed to the Blood by the Lungs, fo are alfo the malignant Qualities of bad Air,
* Vi , ' ■ \ .
71. Thus alfo the putrid Water in marfhy aguifh Countries, may be a Caufe of Agues, as well as the putrid Air which they breathe 5 which, as well as the pu¬ trid Water, may probably carry fome of its putrid Quality into the Blood thro' the Lungs. This Method therefore of fweet- ening (linking Water, by blowing Show¬ ers of Air up thro" the (linking Water of fome aguifh Places, may be beneficial*
72. Live Fifh may well be carried feveral Miles, rby blowing now and then frefh Air up thro' the Water, without the Trouble of changing the Water 3 for this Ventilation will not only keep the Water
* E fvveet.
58 111 tafied , &c.
fweet, but alfo enrich it with Air, which
is neceffary for the Life of Fifhes 5 with
which Air they fupply their Blood, by
breathing the Water, thin fpread, between
their Gills ; But ftjnjdng Water will kill
FHh.
73. I have found that much of the heating Oil may be got out of Tar-water5 by blowing Showers of Air up thro’ it when fcalding-hot, for if or 30 Minutes, the longer the better 5 the lefs volatile^ and more falutary Acid remaining*
t
/
m
\
[ 59 J
A N
APPENDIX
T O T H E
Treatise on difilling Sea-Water, fweet- ning Milk, &c. which gives a farther Ac* count how to procure fill greater Plenty of Fresh-water at Sea , and to fweeten ill* tafled Milk , Stinking-water, and mujly Li* quors, &c. by blowing Showers of Air up thro them .
74. OEVERAL confiderable Improvements hav« ing been made on the Subjects of this little Book, fmce the Publication of it, I fhall here give a fhort Account of them, hoping they may in fe- veral Refpeds be of Benefit to the World •, efpeci- ally the great Improvement in difiilling Plenty of Frefh-water at Sea,
75. In order to bring the Method of procuring Plenty of good Frefii- water at Sea, into pradice, fe- veral previous Trials were made, at the laudable Motion and Defire of Peter JVyche, Efq-, in a Still containing 24 Gallions of Water, at MefTVs. Steel and Stephens's Copper Workhoufe, near the Falkon - Stairs , Southwark. The firfi: thing to be done, was to find out the proper Size of the Diameter of the Copper Air-box. The Diameter of the Still, near its Bottom, being 19 Inches, the Diameter of the
E 2 firfi:
6o APPENDIX.
fir ft Air- box vvas 184-I Inches. On three feveral Trials, a JVmcheJier Quart ot Water was diftilled in five Minutes by the common way of Diftiilation ; and by Ventilation a Quart was, in 3 or 4 Trials, diftilied in 2 Minutes *, but at the Diftiilation of the ninth Quart, the Water was fo much cooled by the ventilating Showers of afcending Air, as to require 5 Minutes and 44 Seconds. Now this great Decreale ol the Quantities diftilled, was plainly owing to the too great Breadth of the Air- box, which hindered the Fire from heating and keeping hot the Water which was above it, to fuch a Degree, as to have no Diftiilation in the common way, for 8 or 10 Minutes after the Ventilations ; for the half Inch Circle of Water which was not covered by the Air -box, was but one nineteenth Part of the whole. The next Trial, in the fame Still, was made with an Air-box, whofe Diameter was 1 3 Inches, its Area therefore 127 fquare Inches ? which deducted from 271 fquare Inches, the whole Area or Breadth of that part of the Still, there remains 144 fquare Inches, for the Area of the three Inch broad annular Circle round the Air-box, viz. 17 fquare Inches more than the Area of the Air- box. The Event was, that in fe- ven Diftiliations in the common way, a Quart was .diftilled in 5 Minutes, fometimes in a little lefs, and fometimes in a longer Time. And by Ventilation 1 4 different Quarts were diftilled in different Lengths of Time, from a Quart in 2 Minutes and 6 Seconds, to 3 or 4 Minutes,
76. I then repeated the like Trials with my fmali three Gallon Still, diftilling in the common way a Pint in 10 -ft and 9 Minutes ; and feven feparate Pints were diftilled by Ventilation in 3 + L to 4 4-1 M mutes. Hence we fee that Ventilation has a more fteddy and con ft ant good Effebt where the Air-box is lefs in Proportion to the Still, than it
was
APPENDIX. 6t
was in the other two Difti nation's : For in this lefTer Still, only 27 out of 99 fquare Inches were venti¬ lated, 72 fquare Inches being un ventilated. It will therefore probably be advifable to have the Air- boxes of other Stills to be nearly in the like Pro¬ portion to the refpe&ive Stills, the Diameter of this Still being 1 1 + f Inches, of its Air-box 6 Inches.,
77. As by repeated Trials a Quart of Water was diftilled in the common way in five Minutes, in the above-mentioned twenty Gallon Still, fo an 1205, or two/^Ewa» and 14 Gallons, may be diftilled byA
Ventilation in twenty Flours. '
/
78. Mr. TVyche , who v/as prefent at the Trials near the Falcon- St airs , obferving the Water in the upper Part of the Worm-tub to be reeking hot, tho’ the Water below it was cool, very rightly pro- pofed to have the hot Water run from the upper part of the Worm-tub, thro’ a fmall Copper Pipe, into the upper Part of the Still, as faft as it was diftilled off, the running Quantity of Water to be adjufted by a Turn-cock in the Pipe. This I tried in my little Still, by conveying the upper warm Water of the Worm tub into the Still thro’ a fmall Pipe Which palled thro’ a Hole in the Head of the Still, almoft down to the Bottom of the Water in the Still : My Reafons for doing of which were, viz. left the iels hot Water, by running on the Surface of the boiling Water, might; confiderably check the Afcent of the riling Vapours ^ whereas, being mixed and blended with the lower Water, it Will foon acquire a due Heat. Another Reafon why I chofe to lead the entering Rill of Water fo flow, was, that it might be intimately mixed with the Chalk, which is there in an agitated State by reafon of the Adlion of the Fire. The Event was as follows, viz. that fix ieparate Pints of Water were diftilled by Ventilation during the running in
62 APPENDIX.
of the v/arm Water, fome in 3 f Minutes, others in 4 Minutes, 4 and 4 Minutes, 50 Seconds, which was the cafe of the fecond Pint.
79. Hence we fee the great Benefit of this inge¬ nious Improvement of Mr. JVyche* s in diftilling Sea-water, where the Still will be filled with the fame Liquor as the Worm-tub 5 but this Method cannot fo well be put in Practice in other Diftilla- tions. The Benefit of thus gently and incefiantly keeping the Still full, will fave about one-fourth of the Time and Fuel, which it would otherwife re¬ quire to refill with cold Liquor, and bring to a dif¬ tilling Heat. This great Advantage, added to that of diftilling about double the Quantity by Ventila¬ tion, mu ft needs both together be of fo great Im¬ provement in diftilling three Parts in four more than ufual, as will be of the greateft Benefit to Na¬ vigation in feveral refpedts. By this means the Still need be emptied and cleanfed from the Chalk, and very fait Water, only at the end of each daily Diftillation.
80. And whereas if all the Chalk requifite for a whole Day's Diftillation were put into the Still at once, it might be fufpedled that fuch a Quantity laying at the Bottom of the Still, might hinder the boiling of the Water: I put into a broadly fiat- bottomed fauce-pan, half an Inch Depth of powder¬ ed Chalk, and two Quarts of Water boiled in ten Minutes : The Water mingling freely, efpecially in the time of boiling, among the thin pappy Chalk, was freely adled on by the Fire. But as in boiling it frothed much, it may be proper to put at firft into the Still only as many half Ounces of Chalk as there are Gallons of Water ; and afterwards from time to time in proportion to what additional Water fiiall have run into the Still, at a Hole purpofely made in the Head of the Still, taking care to venti¬ late
APPENDIX, 63
late while the Chalk is putting in, which will caufe it to mix intimately with the Water, and thereby have the better Effect on it. And perhaps a lefs Proportion of Chalk than half an Ounce to a Gal? Ion of Sea- water may furfice.
81. The Degree of Fulnefs or Emptinefs of the Still* may be known by putting a fmall floating metalline Veflfel, in at the Chalk Hole, with a long flender Wire to it*
82. Mr. Wyche thought of other Means the bet- ter to promote Diftillation, viz. by conveying the Air from the Bellows through a Pipe with feveral fpiral Coiles, thereby in palling thro5 boiling Wa= ter in the Still, to make the afcending Showers of the Air the hotter, and fo the lefs refrigerating, Alfo to have the warm Water pafs from the Worm- tub, in a Pipe, with feveral the like fpiral Coiless in the Head of the Still ; thereby the more to heat; the entering Water. But we find* by the above- mentioned Experiments, that there is no occafion for either of them j but if wanted may be ufed.
83. As to the Benefit of Ventilators in preferving the Health and Lives of People in Slave and other Tranfport Ships, I have received farther Confirma¬ tion of their great Benefit, in a Letter from Dr* j Demainbray, who has (hewn Courfes of Experimen¬ tal Philofophy to his Royal Highnefs the Prince of Wales and Prince Edward , viz. 44 That in the Year 44 1753 Ventilators were put into the Veflels in the 44 Slave Trade at Bordeaux , and in other Ports of 44 France ; the happy Effect of which was, that in- 44 Head of the Lofs of one- fourth of thofe valuable 44 Cargoes, in long Paflages from Africa to the 44 French Plantations, the Lofs feldom exceeded a 44 twentieth, And fince my Return to England , I
E 4 44 have
64 APPENDIX.
have been informed of a French VefTel, which 61 by this felf- evidently reafonable Precaution, faved 308 out of 312 Slaves, fpite of moft tedious Calms and a long Paftage. And Dr. Garden , in his Letter to me, dated Cbarles-<Totut)n , South- Caro¬ lina^ March 24th, 1756, fays, viz. “ It is indeed very wonderful, that the Slave Merchants do not come into the Ufe of Ventilators. There are “ few Ships come here from Africa , (even though 44 they call for frefh Provifions and Water at the 44 IJlands) but have had many of their Cargoe cc thrown overboard *, fome one-fourth, fome one- third, fome Iofe half ; and I have feen fome that €c have loft two-thirds of their Slaves. I have of* £C ten gone to vifit thefe VefTels on their firft Arri- 64 val, in order to make a Report of their State of Health to the Governor and Council ; but I ne- 66 ver yet was on board one, that did not fmell st moft offenfive and noifome. What from Filth, 44 putrid Air, putrid Dyfenteries (which is their 64 common Diforder) it is a wonder any efeape 44 with Life.'5
84. A probable Means lately occurred to my Thoughts, tho5 not perfedlly to cure, yet much to abate the great Degrees of {linking of the Bilge- water in the Well of Ships, viz. by laying at the Bottom of the Bilge- water, round the Main-maft, Copper Pipes full of very fmall Holes, not one twentieth of an Inch in Diameter ; and blowing Showers of Air up thro’ them from fmall Black- fmith’s Bellows, fixed out of the way, within the Well. Such Bellows may be worked with great Eafe, for one, two, or three quarters of an Hour, in every 24 Hours, more or lefs, as fhall be found requifite by Experience : But with this Precaution, that whenever the Water (links much, firft to pump it out of the Ship, and after letting in fweet Water,
then
APPENDIX. 6$
then to ventilate it a little now and then, as fhall be found needful ; but care muft be taken not to ven¬ tilate very ftin king Water, becaufe it may increafe the Unwholfomenefs of the foul Air in Ships. By this means Ships will probably be made fomething lefs unhealthy •, for the putrid Vapours which arile from {linking Water, muft needs greatly contribute to increafe the Putridnefs, and confequently the Noxioufnefs of the foul Air in Ships. This Pre¬ caution therefore, with Ventilators frequently to con¬ vey off the clofe foul Air, will be effectual Means to make Ships much more healthy ^ as will the changing the foul Air in Goals, Hofpitals, and Tick Rooms, with proper Precautions, make them more wholfome : And it is with pleafure that I ob~ ferve, that thefe falutary Means are coming more in ufe in Hofpitals, &c. either by means of Venti¬ lators, or by admitting frefh Air in fmall Quanti¬ ties, and thole fpread in thin Sheets, fo as not to have the entering Air blow diredlly on, and incom¬ mode the Patients. Where it can be had, a tho¬ rough Air entering on one fide, and paffing out on. the other fide of Wards or Rooms, will be heft ; becaufe the Change will be almoft conftant, and may be as gradual and gentle as we pleafe. I fhall give a more particular Account of this in my fecond Volume of Ventilators.
85. As to the curing the ill Tafte of Milk from the Food of Cows $ and aifo curing mufty Liquors, I made the following Trials, viz. When in the Be¬ ginning of March the Turnips had made large Shoots, and were thereby become very rancid, two Cows being fed with Turnips only for feven Days, their Milk had a very difagreeable Smell and Tafte. On ventilating it Raiding hot, with afcending Show¬ ers of Air, at firft the ill Smell increafed, but in two Minutes that Smell was much abated ? and
with
66
APPENDIX.
with five Minutes Ventilation, there was only the common Smell of good Milk; which fhows that the rancid Oil of Turnips, which gives the ill Tafte, is very volatile : After ten Minutes Ventilation there was no ill Tafte or Smell ; and it was the fame after 15 and 30 Minutes Ventilation. By this means therefore the ill Tafte of Milk from fomc Food of Cows, may eafily be cured. Experience will fhow what Degrees of Ventilation will be re-* quifite for larger Quantities of Milk ; as alfo for curing the ill Taftes from different Kinds of Food 5 as alfo from the ftiorter and longer Times of feed¬ ing on fuch Foods. It is obferveable that the Breath of thefe Cows was difagreeable ; whence we fee how freely contagious Infections may be con¬ veyed through the Lungs, from tainted putrefcent Blood*
86. A Cow having been fed for fixty Hours with a good Quantity of Crow Garlick, mixed with cut Grafs, towards the end of June , the Milk had a very difagreeable Smell and Tafte ; which was not cured, though fomething better, after 30 Minutes Ventilation, while fcalding hot. I re¬ peated the fame Ventilations for 15 Minutes, with the two following Evening and Morning Milks of the fame Cow, viz. 12 and 24 Hours after the Cow had left off eating Crow-Garlick ; at which times the ill Tafte and Smell was fenfibly abated before Ventilation, and fomething more after it, yet was far from being cured. Hence we fee that the ill Tafte and Smeil of the Crow-Garlick Milk, cannot thus be cured, tho’ fomewhat amended,. The ill Tafte of this Cow’s Milk continued for about five Days after fhe had left off eating of the Crow-Garlick. And perhaps where Cows have eat¬ en but a fmall Quantity of it, the Abatement of the ill Tafte may be fo conftderable, as to recom-
5 pence
APPENDIX 67
pence the Trouble of ventilating it. As Oppor¬ tunities offer, I will make the like Trials, with other ill-tafted Milks, fuch as that from autumnal Leaves, &V. and hope that others will do the like.
87. Cream or Milk Sillabubs may moft commo- dioufly and eafily be made in Plenty, in a few Mi¬ nutes, by means of a fmall Tin Air-box, three Inches in diameter, and three quarters of an Inch deep 5 the flat Bottom of the Pot, which contains the Cream or Milk, to be but little wider than the Air-box, that the Air from the Box may the better come at it : But the wider and deeper the upper Part of the Pot is, fo much the better, for the Froth expands muchw
88. Scalding-hot mufty Vinegar was cured by repeated Trials, of near three Gallons in each Trial, by ten Minutes Ventilation. And giving Vinegar a fcalding Heat, does not weaken or damage it, as it does Wine, whofe vinous Spirit is carried off' both by Heat and Ventilation ; for when feme ftrong mufty Raifin Wine was ventilated hot, it was cured in five Minutes : But the vinous Spirit, which ftrongly affedted the Nofe in flying off du¬ ring Ventilation, being gone off, the vapid Wind would not kindle into a Blaze, when thrown into the Fire, as it did to a great Degree before it was heated and ventilated. Neither mufty Wine nor Vinegar were cured, tho5 fomething bettered by 30 Minutes Ventilation, when cold.
89. Mr. Jones , a Chemift in Cr anb our n- Ally, Leic eft er •Square^ ventilated a Gallon of Proof Male Spirits 1 5 Minutes cold, in which time it wafted two Ounces and half ; whereas a like Quantity of common cold Water wafted but half an Ounce in 15 Minutes Ventilation, vte, but one-fifth part of
what
68 APPENDIX;
i
what the Spirits did ; and the fame Spirits ventilated hot, wafted . no lets than 5 Ounces in 5 Minutes % which Ventilation made them fenfibly better tafted than the unventilated. But the great Wafte {hows that thefe volatile vinous Spirits, ought not to be ventilated, neither hot nor cold. Befides that, the 15 Minutes cold Ventilation had but little Effect in bettering the Spirit.
90. In order to know whether Fifn in a Veffel of Water would live the longer for having Showers of Air blown up thro9 the Water, May 25; 1756, at feven in the Morning, the Wind N. E. the Mer¬ cury in Farenhei? s Thermometer, 50 Degrees, and it continued fo cold, that at one o’clock it rofe but to 60 Degrees ; I put twelve Dace into a Fail A in two Gallons of frefh Fond Water, thro5 which a Stream ran, and twelve more into a Pail B , with the like Quantity of Water ; one of which Fifties in B was Tick, as appeared by turning its Belly upwards 5 as were alfo two Fifties in the Fail A, which was occafioncd by being all brought in a Pail above half a Mile from the Thames .
91. At 45 Minutes paft 8, moft of the Fifn in the Pail B , were turned Belly upwards, and lay as dead ; at 30 Minutes paft 9 feven of them were dead *, at 30 Minutes paft 1 1 all but three were dead *, at two o’clock but two Fifh remain alive in B ; which remained alive, tho5 fick,' at ten that Night, viz. at the. end of 14 Hours.
92. The good Effect of blowing every quarter of an Hour, with 25 Strokes each time with dou¬ ble Bellows, Showers of frefh Air up thro5 the "Water, was, viz. they all continued well, and the larger of the two fick Fifh recovered ; but the lef- fer died at 4 o’clock, viz. at the end of nine Hours ;
5 upon
APPENDIX. 6g
ypon each Ventilation it turned its Back upwards hut foon after the Ventilations, it conftantly fell precipitate with its Head foremoft, to the Bottom, and there turned Belly upwards. After 4 o’clock the ventilated Water frothed with larger Bubbles, this owing to the Slime of the Fi(h. The laid Ven¬ tilation was at 10 at Night, when the- Fifli in the ventilated Water were well, and would probably have long continued fo by the Salutarinefs of Ven¬ tilation •, but that being difcontinued, they were all found dead the next Morning, except one which had fome fmall Degree of Life.
93. June 7, the Wind S. W. cloudy, the Ther¬ mometer at 58 Degrees, 13 live Gudgeons were put into two Gallons of frefh Pond-water in a Pail A\ and a like Number into a Pail B , at 10 Mi¬ nutes btfore 7 in the Morning. At 50 Minutes pad: 7, two in B began to be fick •, at 8, half of them came up for Air, and fhowed Uneafinefs ; at 15 Minutes pad: 8 two are dead •, at 30 Minutes pad: 8, eight more turned Belly upwards , at 8 Minutes pad: 9, five are dead in 5, and five more fick •, at 30 Minutes pad: 9, feven are dead, and four fick, two well ; and 30 Minutes pad: 10, eight are dead ; at 1 1 two only alive, and alfo well, though they fhowed fome Uneafinefs by their raiding their Mouth to the-Surface, which they continued to do till nine, when they were taken out of the Water. Hence we fee, by this, and the preceding Experiment on Dace, that one or two Fifli may be kept alive many Hours longer than a greater Number can be, by means of the fmall Portion of frefh Air, that is continually mixing with the Water, on which it pre fifes.
94. The Water in the Pail A was ventilated from 10 Minutes before 7, to 6 in the Evening, by
blowing
fe APPENDIX.
blowing every quarter of an Hour Showers of frefh Air up thro* it, with 25 Strokes of the Bellows ; by which means the Fifh continued all well, laying quiet at the Bottom : At fix we ceafed to ventilate ^ for an Hour and half after which, there was no Signs of Sicknefs *, after two Hours two of them jfhowed Signs of Uneafinefs •, and at nine moft of the Fifhes turned Belly upwards, and lay at the Bottom dead or dying. By comparing this Event with that at eight in the Morning, we fee there is more Air in this ventilated Water than in the Pond- water, as is probable by the Gudgeons living longer in it, without Ventilation, than in the Pond- water. And accordingly the fpecific Gravity of unventi¬ lated Pump Well-water, was a very fmall Matter greater, than that of the fame, after being ventila¬ ted with 100 Strokes of the Bellows, as I found by the Hydrometer -9 and there was nearly the famq Difference between the fpecific Gravity of unventi¬ lated and ventilated Table Beer.
95. Tho’ from thefe Experiments it is manifefl, that Fifh die for want of conflant Supplies of frefh Air in the Water, yet when taken out of the Wa¬ ter very lively, they foon die, notwithflanding the Surfaces of their Gills are then expofed to the im¬ mediate Contact of the Air ; which fhows that ei¬ ther the Air does not enter from the Gills to the Blood, from the open Air, as it does from the Wa¬ ter ; or that the Circulation of the Blood is flopped by exchanging their proper Element, Water, for Air ; as the Circulation of the Blood of Land Ani¬ mals is foon flopped by immerfing from Air into Water.
96. Hence we fee the Benefit of frequently re- plenifhing the Water with frefh Air, which- we End is neceffary not only to preferve the Life of
Land
APPENDIX. 7i
Land Animals, but alfo of Fifh ; as alfo the Ufe of ;heir Gills, to fpread in thin Sheets frefh Supplies pf Water, that they may the better come at the Air in the Water for which Purpofe bo h Sides of their Gills are furrowed with many fine Furrows* not only thereby to enlarge their Surfaces, but alfq more minutely to divfde the Water, whereby to pome at the Ah in it,
97. Whence we may reafonably infer, how re- quifite it is, in order to keep the Blood in a falu- tary State, to have almoft conflant Supplies of the Breath of Life, frefh Air, to mix with it : For if the principal Ufe of the Gills were only to coo!s and churn, and comminute the Blood, Water de¬ void of Air could as well perform that Office, as Water repleat with frefh Air. It muff therefore be of Importance for all Animals to have fo neceffary a vital Fluid frefh and pure, and not foul and pu¬ trid,
98. A Fifherman informing me that the Fifh were apt to die in the Well- boats, it occurred to me that it might, in a good meafure, be remedied*, by fixing upright a Board of a proper Breadth at the Outfide of the Boat, as long as the Well is deep, on that fide of the Well which is next to the Stern, and opening at an Angle of about 45 De¬ grees towards the Head ; which, by checking the Courfe of the Stream of the River near the Boat, will raife the Water a little, and thereby caufe it to run into the Well on that Side, and out on the other Side of the Boat *, and the Run of the Water thro5 the Well, will be more accelerated, if a like Board is fixed in the fame manner on the other fide of the Boat at the Side of the Well next to the Head of the Boar, but opening towards the Stern at an Angle of 45 Decrees, by which means the
Water
72 APPENDIX.
Wafer will be lowered on this, as much as it is
raifed on the other Side of the Boat. - Another
Means to have a brilker Current of Water thro5 the Well, would be to moor the Boat in a fixed Pofi- tion aerofs the Stream v/hen it can conveniently be done. I am informed that there are PafTages from Head to Stern, for the Water to pafs freely thro3 the Fifh-Well of fome VefTels. We fee, from the Event of the above Experiments, the Importance of frequently changing the Water in the Fifh- Well of Ships, efpecially when there are many Fifties in it. Hence alfo we fee how falutary it is to Fifh, to have the Surface of the Water agitated into Waves by Winds, whereby Plenty of frefh Air enters, and is blended with the Water.
F 1 N I S.
I
h 1 1