RECORD: Darwin, C. R. & Horace Darwin. 1873.08.21-28. Large Purple Plums. CUL-DAR66.9-14. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 3.2023. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.

The volume CUL-DAR66 contains notes on 'bloom'. Francis Darwin explained: "His researches into the meaning of the 'bloom,' or waxy coating found on many leaves, was one of those inquiries which remained unfinished at the time of his death. He amassed a quantity of notes on the subject". LL3: 339. See an Introduction to these folders by Christine Chua & John van Wyhe.


[9]

Down Aug 21 1873

Large Purple Plums —Green & Hard

2 Rubbed put in cold water & and put in a bell-glass place at 72°

put in at 6. 20 PM

At 10 8 PM those in bell glass were 74°

(Aug 22nd those in bell glass were 74°)

2 not rubbed in water as in preceding

put in at 6. 20 PM

2 not rubbed in cold water at ordinary temperature in the study

put in at 6. 20 PM

At 10 PM these were 63°

do Aug 22 at 7.30 Am

Aug 22 11.30 A.m. 65°

9. 45 Pm 64°

Aug 23 63°1/2 7 Am

 

All these were placed in 4oz of water

Aug 22' temperature 74° at 1045 AM

76° 9.45 PM

Aug 23rd 76° 7˚ AM

All taken out at 8.25. A good deal apparently of the bloom floated in the water from unrubbed flowers

All slightly acid to the same amount by litmus paper. All taste the same have a strongish taste

all the blooms feel hard.— No effect produced by the immersion

[10]

Down Aug 21st 1873

Strawberries

2 placed in 2oz water in bell glass at with the plums at 72° Taken out at 10 9.45 AM on Aug 22nd

The water in wh they had been was very much discoloured

Temp. at wh. they were taken out 74°

To 3 portions of the water from this I added 7 portions of water from the ones that had been in cold; the diluted solution was very slightly the darker The diluted solution → is roughly of the same degree of acid as the strong sol. of cold straw-berries. I tried this by litmus paper roughly. The concentrated solution of hot straw-berries is much more acid than the other. The hot solution turns the litmus paper markedly; the other only slightly.

2 places in 2oz of water in the study

Water slightly discoloured at 10.45

Tem at 10 P.M. Aug 21st 63°

Aug 22nd. 7.30 temp. 63°

The diluted solution (diluted as so as to make it of nearly the same colour, as above) tasted different, not so acid & sweeter.

I placed 6 drams in hot-cupboard at 10.50

The strawberries in the hot warm water were much more squashy.

[11]

Down Aug 22 1873

Yew berries

7 yew berries put under the bell glass at 77°, in 1/2 oz of cold water at 2.50 PM. They were washed in Sulfuric Ether for a few seconds, wh. removed the wax & therefore were wetted. Aug 23 temp 76° at 7 AM

Taken out at 10.15. No apparent difference from those below. — Cd ether have hardened or modified surface — The water did not appear more viscid.— Water not coloured. —

7 also placed under bell glass in natural state, these floated whilst the others sank; but they were made to sink by a piece of zinc. Aug 23rd temp 76° at 7 AM

[12]

Down Aug 23rd 1873

Cabbage leaves:

1 in rubbed 6oz of cold water placed under bell glass water kept warm at 75° completely covered with water. Weight 43.8 gr (Red wafer)

Time 11.25 AM 2 PM. 79° 6 PM 64° Aug 24th 7 AM 77° 1/2

Aug 24th Taken out at 2 PM Weight 60.1

1 not rubbed in bell glass water kept warm as above (Red green wafer)

2 PM 79°. Weight 54.6 gr

6 PM 74° 9 P 8.40 PM 78°

Aug 24th Taken out 2 PM Weight 48.75

These were dried by blotting paper

1 in cold water (the surface having been rubbed & all bloom taken off) in the room at 65° at 11.25 AM

2 PM. 79°; 6 PM 74° 6.10 Pm. 66° 8.40 Pm. 65°

Aug 24th 7 AM. 65° 1/2 (yellow wafer)

Some 1/2 oz of water was taken in which all 3 leaves had been immersed & a Drosera leaf put in, at 1˚ 55': At 2˚ 2' (ie in 7') some slight inflection in the rubbed leaf in cold water & in not-rubbed leaf in warm water.— At 2˚ 5' the Drosera rubbed leaf in cold water was most inflected, & several thought that this leaf smelt the strongest.

I thought, (but not others) than the not-rubbed leaf in warm water smelt the least. At 5˚ P.m. the Drosera in water from rubbed leaf in cold water was immensely inflected; & there was some inflection in the 2 other leaves. On the 25' at 9˚ 30' these lea latter leaves were fully reexpanded; & the leaf in the water from rubbed leaf in cold water was ↘

[12v]

beginning to reexpand. We may safely infer that some albuminous matter exuded!! (One oz. of fluid from all 3 cabbage leaves was evaporated & the residues from the leaf with its bloom appeared to us all much less than from 2 other leaves, & in a conspicuous manner less coloured. That from leaf which had been rubbed & kept warm, was plainly greener-yellow & apparently more in quantity. The dishes were washed in disc of water & this was again evaporated & with the same results as before

Some of the residue was scraped off & put into heated platinum crucible, but did not smell of animal matter.

I wish I had burnt it.

The trial ought to be made with several leaves— Water at about 70° F

[13]

Down Aug 23rd 1873

Centauræ

1 leaf in natural condition place in cold water & put under the bell glass at 75° at 11.25

The leaf with white worsted was rubbed under water also under bell grass

2 P.M. 79° 6 PM 74° 8.40 PM 78°

I was not able to ascertain whether the water reached the surface of the leaf— No difference in the water in which the 2 leaves were placed at 10˚ on 24th

No difference

[13v]

The water in wh they were was evaporated and there was a slight film of white substance; there was no difference in the amount or in the taste

(1

Down

Grapes Aug 26 73

Taken out at 2 temp 81° in bell glass

In the room 67°

Red Rubbed in Hot Big evaporating dish

Green Unrubbed in Hot next [illeg]

Yellow cold not rubbed smallest.

All equally hard—

No acid in any of them

"Red tastes most. Other two nearly the same" (George)

Very little taste so little I cant tell wh. is the strongest

Put a little less than 1 oz to evaporate so as to make 1/2 the original quantity of liquid that was in the glasses

In the red there is a good deal of floating matter, wh makes it not look bright like the others no difference in colour except this.

A little sediment in each but no apparent difference in the amount

/over

(p 2

Grapes)

Aug 27

Put the unrubbed & rubbed grapes (those that had been in the hot water before) under the bell glass at 2.45 2˚. 52' in an 1 o 2oz of water each.

tem at 2˚. 52'— 76° before lamp lamp was placed under the bell glass; 3˚. 2' PM temp 75°

3°; 35' 82°

6°. 37' 90°

Aug 28th 8˚ 35' AM 86°

Taken out at 3.45

Great quantity of floating matter in both.

Most in the rubbed solution in wh rubbed grapes had been. No difference in the grapes No acid.

Strong taste to both, if any difference the rubbed ones the a little strongest, 1 oz of each of sol. put to evaporate

Unrubbed in the smallest evaporating dish.

Rubbed in the middle sized one.

I can perceive no marked difference in quantity in the 2 dishes.

[Repeat of image 8]

[Repeat of image 9]


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 25 June, 2023