58. THE GARDENERS’ CHRONICLE 151 
seated 
i of fi fluid by the main stem altogether | upon the same Apr: npr astonishingly closely y with | | increased until it became exclusi sive. During the per 
f èy, that the los quantity absorbed from t re o colur n n of Vine sap of the height of | | sistent drought in the middle of f May an" column of 
1 os flows at any tim oe. ~~ day ee | the v erti o e the poin ts o of ; die y & ould be raised by abunds antly wate ering the 
; r discovered 1s ine, from 7 P.M, to 8 a. t 
a: rags Dg rent heights up pon branches | the actual eint ce dletation of the m ercury is 13.1 in nches), while the mereury in a tu é fix x as 
pesuring ta v1 ne indicated. a difference of pressure of | aller ssure te the Vine generally is in- | neighbouring i ine not wW atered constant Map = 
dem hich : rale Aar ta to the pressure of | cre casing, or greater when i t is decreasing. more st riki ng was the influe of watering in 
2 pad The ect or reclining position of parts of the Vine | | sae middle ‘of June; it raise ed the _ mercury in 
apie these very | 24 403 to 603 war. (15.8 to 23 .7 inches 
of the two ct Toke oF the s eh vise haved] slight a sane upon the tension of the sap. For | B q t accid pep of presak 
gndiaied tha tension of the sa . contained i in them, | example : the measuring-tube was fixed vi an metr sap, tl xists in those par otis sof e Vine ahve 
s regards mrika tober; the very >| ( horizon - v| kinana not isolated a daily varis ti ion (eor is ay 
Rich ressure Meee in tees fixed low | tally- -placed Vine, measu ring 4.92 metres des? arin =) | | Hales) which the e 
Sto be ‘att ak ibute ed to, the aeta pressure | in its PEAN length. On the Vine bei eing fixe bursting of the buds, is evid d pp es 
of fi 
| 
ri c 
Siis o uid 
gued 
= 
? the Vine e | upright posit ion, “the mercury rose om ka 3 re 696 judgm ent of all obsery ers, roni: er upon the e ev apora- 
above the place where the > measuring b 7 in nche s) in four “hou urs, , When the Vine ijon from the 1 leaves. The degree of variation, very 
o assum 
; at |v ] to the degree of humidity of the air 
of the vessels ae ot containing z air | ( 128 3 and the 1 beg gan to ascend. again | | on particula ar day: ys, increases on the whole constantly 
n the 
e| 
| 
A fid, originat y ais £ lu pidly Other ‘Solar experiments Hit still far | with the bribe of the shoots. At the end of 
0 
medullary ll f the pig ae atin April, in dry air, the maximum was 23 =a 3 inch), 
mehes, “ a by me: ans of t these | of the about 360 mar ihan required by Briicke’s | and at the beginning of May 40 ch), i: 
soluble or expanding in bulk in water, first | hypothesis. third of the same Bray 100 (3. inches) and at the 
A iont with water, and then, as they still | All these phenomena indi cate that the cause of the end of iol already 400 (15.7 eee an e, till at 
sic om water, that which they coul t stow | t Į yod ength the e vapo oration Sale the the 
` ity ee ge tion of | situated ab ground; that the action of the urging | tained in the Vine, that Bor Bo the night the 
Scared m stance, as sap, i neighb ouring force in those parts of the Vine furthest removed fi 
te only by the b 
round i $ egi un 
sinal n the atoe the vertically elevated mass of sap, but also by the | more than 200 MM. (7.8 inches), and in the middle of 
pri branches, and Arei iaer bY gravita- | opposition of numerous mem ieran. through oa the | July 33 xo. (1.2 inch). In accordance with previous 
would sufficiently explain why the lower | sap must ta ke its course. This conjecture i is nce | accounts I found the daily — a few hours after 
of Vines generally bleeds earlier than the upper. | ¢ by pn sg the minimum did not occur as a rule until 
probable that the sap flows in the spiral | is ay bare near to the main rad cut | sunset. 
vessels, at the time of the yearly and daily maximum of | though, e tag t d he part “The rapid alteration of the pressure of the sap ey 
bh gh ds but downwa rds. the root running into the earth, another upon the f the degree of ng of the 
f vith the st f the Vine, | is very remarkable, On the 24th ay at widen. 
l suai with one hed aa most essential re of | a very considerable difference of el is | with a br wind, i the mercury of a 
the phenomenon, a erst is ane. aei 2 wy big domins rteak in the tw a, “he bala being gauge kei aA à pae “of 59 MM. (2.3 inch); at 
l researches of i which L. r “about t again mig is ee on 30 P.M. a moist west wind arose; in spite of the 
with t The ymi increases | burning sunshine under the clear sky and the increase 
the experiments more widely, and in whee to ee rapidly w with the siamo of iy season. In the begin- of temperature about 3° rah ba a hog the height of 
| a, ing o of June, 150 to 250 um. (5.9 Pathe nches) ; in the | the mercury at 1.30 P.M. w tM. (3.1 inches); at 
Not only the d f June, 500 mat. (19.6 inches); the end of June, | 8 p.ar.,the a paneeine hating enn slightly clouded, 
vari the Vine xo Tew me sap Birch, 600 t to » 700 MM. (23.6 to 27. 5 inches), when the, tube 368 MM. er ine 
deciduous trees, Roots goi 5 only into the ground display no varia- 
the “Conifera), contain dn the the mercury at all times of the day. Hence it certainly = co mparable with "eis in i shoots above the 
d k ani AA fa ce f 
of m in 
u ying in a fluid, which in| Not however in the e points of the roots and their Pata s fixed upon E Mack > Tegularly, corres 
the vessels formsa thin layer entirely investing the wall, | younger portions. One- year old Seite ie bed spo nding to the degree eot bay of the soil. It was 
-cells is present in greater abundance, ag 110 um. (4.3 inches) long and 3 iffer nt w ith sha Tow ots running ho orizontally at a 
d ends of the vessels, and n dia amet er, When suita ably fastened to ga ys S 0) et donk of KAR A ABD (19. inches), in which the 
; , produce either os 4 nly absorption of water from the soil during the day was 
-cells diminishes replay á a very slight “ascent of the mercury (at most 5 mm., | notably interfered with by the drying effect of the 
eeding begins. In the vessels, | 0.19 inch). sun’s rays. There was found a daily variation, yer i 
ly disa sappears, even at the The bleeding of the Vine is no more limited to the the minimum in the evening, of as much as 
ce of sap; in microscopic | spring sate ed than is the same phenomenon in other (2.7 inches), in some conditions 100 xxt, (3.9 atta a 
thin longitudinal slices plants, Iti is true those e parts abov ve groun nd TAn ttl F RR cke has already pointed o out that cdi continued 
ery elongated ne Miye in | out sap at an l t length 
and wide vessels. It is = fst enves But roots cut across bleed all ti through a deceptive results. (My. rr rk ie hif. deduced 
ngs and may be readily shown asi The force with which the sap issues is not I st for five e days 
t the re of even a tolerably large ins ii thet summer months thani in those of spring, and a T the same cut ys Two phenomena occurring in 
a space enclosed b tubes used for a long time deserve especial mention. 
no obstacle = the passage of | i e 21a = umn of y mercury of 699 Already ¢ on the third or fourth day the Ken variation 
twards thro hrough t the membrane under Ee e TB inches): ka a July 3 of 618 MM. (2 4.3 inches) ; | was shown in far less egree than in tu newly 
8 one of 748 mM. (29.4 erp August 1 — placed on other shoots of the same Vine. The 
f the tension of the e sap of the Vine, ime OF BYE hat. (ORS es); and on September 1 o; branch sub 
liptatioes of of the same Vine cut off | of 355 arm. (13.9 inches). On the other hand the os mitted to experiment are at this time A no. means: 
i elevation of the mercury tity of sai flowing out within a given 4 is far clo: logge ‘ged u The inferior permenbility c of — walls and 
in the tubes situated | smaller in the advanced season than ins me ons Lows ee ie neighbour: ing cells only d 
.6 grams) | alte; of 1 
etres (5.9 inches) | 24 oie ir 
evation, at end of April | per hour ; on July 9, in the same rom a also | de or by the microscope. ° i 
28.7 inches), | of 11 mx. (0.43 inch) diameter 1 119 eee (18.8 | experi ery low-placed weak side chi 
positi he atA at the end hour. With this that | strong Vines, these were enai killed in a few 
a tube fixed at the same time 2.066 meters | the mercury reacquires its Hime aeration gor the | the aA sank in a s: hree da: 
above A gr nd, the aRar ascended | tube is Ph gredas after having been rem oved fór several | never to rise again. The w had thick examined 
nn w n here again the daily ae rse of the sap allowed, far more | and dead. 
Hales was marked | quickly in spring that at rng ee on May 8 in| The powerful forcing upward of the sap by the roots 
ecidental alteratii ped bo July a in 31 hours. en the tube was/is no more restricted to the small num) retell of woody 
of al abundance of moisture, | re ed from cut root fon e July 22 to 25, 48 | plants in which “bleeding ” has been 
og aye rise or fi gnised Ha oe eect ba ia 
earlier, and in greater | rte, of the mercury was again attained. contrary it is quite a universal and permanent pheno- 
ly variation too is | evident how much more slowly the loss of sap by ‘the | menon, Pikk itself in many herbaceous plants | 
a 
> 
g 
is 
in 
the higher tubes. gic Percy laced in summer than in far higher degree than in m ay ro, 
Tange of the daily variation in the External ir set exerting a eae is ect upon sron we will give à few maxima pressure of 
especially xhibited | th on of the sap, ar the observed on rooted plants cut 4 close close above ae 
ot May and the beginning of June, and the kemidi ity both — soil and rthhoaphe re. The Biound: Se 
under f the influence of MM. 
i Atriplex hortensis t 
amounts to from spring, eed soil A of the map, wh attain "an rip! anther Pb ee 
ents in tubes, of pron el of the present year (1856) o April 24, Pave a ee ae ees 
1.210 metres (47.6 ‘gprs rte it T Š imperceptible i in eondeguenne of Morus alba Kea Pak l AAR i Beige, 
A to 05 inch) in | the unusual depress mperature from the 20th | to which may I found on roots dug up 
oe + (17.5 inches) | to ‘the | 30th of sy. “(nein n temperate of ge days, fr as pains i ig injury and placed in water, 
years ol ‘shoot of 11 or | calculated from t an 3 ; 
diameter. ) 
Fieve: Fat š a eee 
F Papave: at 1 04 my 
same Vine which on April raised the Pehia ayeas 0.2 
978 (10.9 inc! column of 804 mm. (31.6 inches) by the Pisum sativum (seedlings) Bt to IO aor 
19inch }| exuding sap, on the 28th, lifted it on the 29th| In all these cases the ascent ascent of the mercury took place 
b- 3 r, . = oe 
of the explanation of 
exceptional occur- i 
iod in the year, 
i cet in the path i nda et bas 
X Dutrochet (“la f el idate it can only in the indicated 
er be inches i o Ga Tos SPORA? Mémoires, Cie "Breede, p. 9D | bt piset by No other probable “i of the 
gino on insufficient. on the he observation a lifting force can be found Sosio the endosmotii 
h eight of the the upper out surfce the root of even very slender DEN iat ate, +3 955 MM. (37.5 inches) high ; Game of the eat 
different heights | and haw long the sap issues, Dutrochet did not make out. eeo tek . (0.39 inch.) ; 
