321. Peaches with grapes and the pulp

of apples.

p. 637

322. Pears included with the pulp of

apples.

638

323. Peaches inclosed with the pulp of

apples and unripe grapes. ib.

324. Peaches included with ale, beer,

and wine.

639

325. Raw beef included with tale beer

and common air.

640

326. Beef included in falt-water and

641

common air.

327. Oyfters with their fhells and with-

out, included in falt-water, common

air, and in vacuo.

348. Hart's-born boil'd foft. ib.

A Defence of the phyfico-mecha-
nical experiments, against the
objections of FRANC. LINUS;
his hypothefis examined; and
his anfwers to particular expe-
riments confidered.

HE objections against the air's
Spring examined.
652

TH

1.

2. The funicular hypothefis examined.

657

643

328. Butter included in a receiver. 643

329. Whitings and wine, and whitings
and oysters included in receivers. ib.

330. Beef with Spice included in recei-

644

331. Larks with beef and ale included 3. The nature of rarifaction confider'd.
663

vers.

in a receiver.

ib.

332. Apples included in receivers. 645

333. A lark included with milk. 646

334. Alark included in a receiver with

butter.

ibid.

4. The preffure and spring of the air

confirmed.

667

5. The elaftic force of compressed and

dilated air measured.

670

6. Atable of the condensation of the

air.

671

7. Atable of the rarifaction of the air.

Remarks upon Mr. Hobbs's Pro- An inquiry into the cause of at-
blems about a Vacuum.

I

SECT. I.

IS often thought that a diverfity of colours conftantly argues Diverity of co-
an equal diverfity in the nature of the bodies wherein they re- lours, what it
fide: but I cannot wholly give into this opinion. For not to fignifies.
mention changeable taffaties, the blue and golden feathers on
the necks of pigeons, and feveral water-fowl, natural and artificial rain-
bows, &c. the colours whereof philofophers call not real, but apparent;
we fee that the contiguous feathers in various birds are fome of them red,
others white, blue, yellow, &c. and that in feveral parts of the fame
feather there is frequently the greatest disparity of colours: fo in tulips,
july-flowers, and other vegetables, even feveral parts of the very fame
leaf are frequently found of different dyes; tho' no difference is obferved
in their other properties. And fuch a variety we have much more remar-
kably in the marvel of Peru; for of the great profufion of fine flowers
which that gaudy plant affords, I have fcarce obferved any two dyed per-
fectly alike. But tho' fuch particulars keep me from affirming, that a
diversity of colours always denotes fome great difference in bodies, yet that
it often fignifies confiderable alterations in the difpofition of their parts,
appears from the extraction of tinctures, wherein the change of colour is
the chief, and fometimes the only thing by which the artift regulates his
procedure in their preparation. Inftances of this are also obvious in feve-
ral forts of fruit, wherein according as the vegetable fap is ripened, by
paffing from one degree of maturation to another, the external part of
VOL. II.

B

the

Remarks upon Mr. Hobbs's Pro- An inquiry into the caufe of at-
blems about a Vacuum.

EXPERIMENTS

AND

OBSERVATIONS

..UPON

COLOURS.

SECT. I.

IS often thought that a diverfity of colours conftantly argues Diversity of coan equal diverfity in the nature of the bodies wherein they re- lours, what it fide: but I cannot wholly give into this opinion. For not to fignifies. mention changeable taffaties, the blue and golden feathers on the necks of pigeons, and feveral water-fowl, natural and artificial rainbows, &c. the colours whereof philofophers call not real, but apparent; we fee that the contiguous feathers in various birds are fome of them red, others white, blue, yellow, &c. and that in feveral parts of the fame feather there is frequently the greatest disparity of colours: fo in tulips, july-flowers, and other vegetables, even feveral parts of the very fame leaf are frequently found of different dyes; tho' no difference is obferved in their other properties. And fuch a variety we have much more remarkably in the marvel of Peru; for of the great profufion of fine flowers which that gaudy plant affords, I have fcarce obferved any two dyed perfectly alike. But tho' fuch particulars keep me from affirming, that a diverfity of colours always denotes fome great difference in bodies, yet that it often fignifies confiderable alterations in the difpofition of their parts, appears from the extraction of tinctures, wherein the change of colour is the chief, and fometimes the only thing by which the artift regulates his procedure in their preparation. Inftances of this are alfo obvious in feveral forts of fruit, wherein according as the vegetable fap is ripened, by paffing from one degree of maturation to another, the external part of VOL. II.

B

the