THE HARDENERS' CHRONICLE 



trbT^uT^Tof the fashion, MM. Cloez and 

 Oeatiolet commence by informing us, with a good 

 tel of ceremony, as one of the conclusions they 

 Sve arrived at, that plants evolve abundance of 

 oxvuen in the sunshine, very litUe in diffused day- 

 SmbS none whatever in the dark ; facts which 

 mere pretty well known and acknowledged before 

 the braking out of the first French Revolution 

 ThU then go on to state that plants never give out 

 carbonic acid in the dark, in which they revive the 

 favourite belief of Senebier . 



.omewhere about the year 1782, following in the 

 footsteps of Priestxey, publ«shed the results of his 

 experiments, and deduced from them the genera 

 conclusion, that in the day-time plants give out 

 oxygen, and that in the night they exhale carbonic 

 acid or fixed air ; in the day-time improving the 



fectory conclusions whatever can be drawn from it. 

 But in truth there is no need to assume that the 

 nitrogen has any such source ; at the commence- 

 ment of the experiment, the plant, it is to be 

 supposed, was in a tolerably healthy state ; and if 

 it was, it would naturally contain a considerable bulk 

 of atmospheric air, as most plants do, and this air 

 would be gradually given out, along with the oxygen 

 evolved by the plant, under the influence of the sun s 



IWU u „. „ light. Hence the first portions of oxygen would 



When Ingenhousz, contain a small quantity of nitrogen ; but, as there 



trate the alburnum 



instrument is 

 lnsumcienc ior raising the bark so as to m i*^ 



the scion, we make use of a small pi ece f u n H 



cut in the form of the scion , such as the feu . »H 



spnWI. tin. ISt and m i„*™l..«:__ r Btt «ln2 



mau uie uiiu ui tue cut maae in the bark tV» 

 merely a slight entry for the scion, which ^n? 

 observed, is cut with a long slant, and a small k 



m 



>4 



moaphere, and in the night deteriorating it, by the 

 _iistton of a poisonous gas ; he was loudly assailed 

 by Sknkbier and many others, who accused him 

 of inventing a foul calumny on plants, and of endea- 

 Toaring to detract from the completeness and per- 

 fection of the whole creation ! They repeated his 

 experiments, but without success, for they could not 

 observe that any carbonic acid was given out by 

 healthy plants during the night; and hence they 

 came to tne conclusion, that the carbonic acid evolved 



in his experiments was the result of fermentation or 

 disease in the plants. To all this Imiknhousz re- 

 plied with a good deal of warmth ; he repeated and 

 confirmed his experiments, and denied that he had 

 in any way calumniated Nature. "I have merely 

 stated what is true," said he, 4< and if it is true that 

 earing the night plants evolve a small portion of 

 carbonic acid gas, surely it is no more calumny to say 

 to, than it is to inert that there are such things 

 ▼enomous snakes, mad dogs, or arsenic, in the 

 world." 



The question thus raised, was, however, not satis- 

 factorily settled, and subseauent writers and expe- 

 rimenters adopted alternately the views of Ingen- 



bousz and of Skneduh ; gradually the opinion of 



Senebier gained ground, and at last, when the care- 

 ful and minute experiments of Pkpy3 were published, 

 the matter was decided ; he found that healthy 

 leaves do not evolve carbonic acid during the night. 



could only be a limited quantity of air in the vessels 

 of the plant, and as it could not absorb any more 

 under the peculiar conditions of the experiment, 

 the oxygen would soon be given off in a nearly pure 

 state ; when this was the case, the tissues of the 

 plant, instead of being charged with atmospheric 

 air, would be saturated with nearly pure oxygen, 

 and a fresh unnatural condition would be added. 

 Chemical action would then begin to get the upper 

 hand over the vital powers of the plant, and it 

 would unquestionably soon become unhealthy. The 

 effects observed in this experiment might be explained 

 in other ways, and there does not seem any sufficient 

 reason to assume that plants are subject to this con- 

 tinual waste ot nitrogen, which, in fact, might be 

 compared to the respiration of animals. As far as 

 we are yet able to judge, the experiments do not 

 warrant such a conclusion. 



The general result, deduced from similar experi- 

 ments, in which various solutions of ammonia and 

 ammoniacal salts were employed, is, in the same 

 way, by no means satisfactory ; and, as a generalisa- 

 tion, could not be admitted. It is stated that water 

 plants are able to obtain the nitrogen which they 

 require from atmospheric air, but not from ammonia. 

 It is quite certain that this does not hold good with 

 common land plants, on the growth of all of which 

 ammonia exerts a most beneficial influence, increas- 

 ing the formation of vegetable matter, and not 

 merely rendering them richer in nitrogen, but, at 

 the same time, by making them more healthy and 

 vigorous, enabling them to absorb a larger quantity 

 of carbon also from the air. Until all the details of 

 these experiments therefore are published, we cannot 

 but feel rather sceptical as to the results ; we doubt 



to bruise the latter as little as possible i ^ 

 to avoid this, the instrument should not o*a Hr 



i.i xi j ~r xi x _ _ i . .. . b° QOWnfcflL 



small A^r 



at tne upper part 01 tne slope, opposite to ^^ 

 The scion thus prepared is inserted in the openi** 1 ^ 

 menced for it, and gently pushed down till ha SjJ 

 rests on the top of the stock. The operation is rfma! 

 for all the other scions which the stock may ^Jj 

 their number depending upon its size. The whok^ 

 placed, they are secured by a split Osier firmly fi !? 

 the stock, and brought two or three times round Si 

 near to the amputated part as is possible. 



We may employ this mode of grafting, in WIB , 

 traordinary cases, without cutting off the top f 4 

 stock, when we would wish to place one or more so* 

 along a stem destitute of lateral branches. This,t2 

 M. Thouin has enumerated amongst the varietforf 



"'rtiw uu nut evuivu eaiuunic aciu during me nignt. MUI * 1CC1 ltt tuu o^c^uvai 0.0 cu m^ iwuiw , wc yuuui. 



The present experiments of Cloiz and Gratiolet I whether the authors, any more than M. Ville, have 





merely confirm that which Mr. Pepys had already 

 proved. 



We pass over for the present altogether the expe- 

 riments on the influence of temperature ; they too 

 do not seem to possess much novelty, though they 

 are probably valuable and trustworthy results. The 

 third series of experiments, those on the influence of 

 the surrounding medium, is that most nearly con- 

 nected with the * periment> of M. Vow, and the 



•eat question of the direct absorption of nitrogen 

 by plants. It is of course impossible to judge cor- 

 rectly of the real value of these experiments, until 

 we know the kind of plants with which they were 

 made ; but as far as the preliminary statement 

 cow, it is certainly by no means altogether sa- 

 tisfactory ; and the remarks we made when speak- 

 ing of M. Villb's results, may with equal pro- 

 priety be applied to these. We have very little 

 faith in experiments made with land plants, 

 plunged under water, and therefore placed in a 

 most unnatural situation ; and on the other hand, 

 it is a very questionable thing to examine the 

 growth of a water plant growing wholly in water 

 and then assume that land plants growing wholly i ' 

 the air must feed precisely in the same way 

 are told that the plants grew well in river water 

 which contained common air, and therefore freel 

 x rogen, provided the water was renewed every! 



established on good evidence, and by clear and dis- 

 tinct experiments, the assertion that plants are able 

 to absorb and assimilate the free uncombined nitrogen 

 of the atmosphere. 



GRAFTING. 



Fig. 13. 





in 

 We 





day, but that they soon became unhealthy if they 

 were kept m water which did not contain air; now 

 it this be true, it may be caused in various ways 



and maybe quite independent of the assimilation of 



nitrogen. 



It is stated by M. Cloez and Gratiolft that when 

 a plant is plunged in pure water, which contains 

 nothing but a small portion of carbonic acid, at first 

 it appears remarkably healthy, and abundance of 

 oxygen is evolved, which is contaminated with 

 n rogen ; that after a time the oxygen comes off in I 

 ess qoantity, but is then nearly pure ; after which 

 the plant begins to suffer. Now setting aside he 

 very unnatural circumstances in which the plan is 

 thus placed, we do not see how, from such an expe- 

 riment, it is possible to conclude that ihl ~ -, pe 



produced by the decomposition of the plant itolf 

 that a fre.h snpply „f f ree nUro „ en ? J'™' «*»». 



mm^ r> <**%& ::ss 



No.X. Section III. — General Observations on Crown 

 Grafting. — The name of this mode of grafting indicates 



sufficiently the manner 

 in which it is usually ap- 

 plied (see Fig. 15), but 

 it is not unique, as will 

 be seen. It is adapted 

 for the regrafting of 

 large old Pear and Apple 

 trees* of bad sorts, or 

 others that are too nume- 

 rous, or that are placed 

 in situations unfavour- 

 able for the variety of 

 fruit which they bear. 

 The stocks ought to be 

 treated in February as 

 the strong trees destined 

 for being cleft-grafted 

 are at that period. It 

 does not make old trees 

 young, as has been stated 

 by many authors ; but it 

 gives them a somewhat 

 youthful appearance by 

 the renewal of their 

 branches. It is an ad- 

 vantageous substitute for 

 the lopping in of good 

 sorts, for the shoots from 

 grafts are more proper 

 for training than those 

 are which spring natu- 

 rally through the old 



~ 







the 



TV 1 bark. 



me I^ n ° W fl,e pro P er time b J the movement of 



S3 "bST r fi? CrV . ed Sh ° 0tS > " fa the ™* ^ clef 

 grafting , besides this inspection, we may assure our 



selves by ^ascertaining whether the bark of the sLt s 

 ^i^J^ tonOminnm, and if so, we pt ted 



with the operation as follows 

 ie wound with a knife ; then mark out the nU *„ 



upon 





l&z&Z fewrSS w-t yiStSS 



m to *i.Ur..„ t a con ? itions of toe experiment 

 ■» *> entirely forced and unnatural, that no satis- 



pene 



Fig. 1 4 



side-graftij 



ceived some moft 

 cations, which 

 shall here detail^ 

 ferring, in the fa 

 place, to fig. U. j. 

 means of a sha 

 chisel, three^ 



tersofaninehbr&i 

 make in the stock 1 

 transverse cut fe 

 whole breadth ( 

 the chisel, and ibd 

 as deep as the tlai 

 ness of a finp; 

 j^ above this, cut 

 with the same W 

 a somewhat \m 

 gular notch, of 1| 



to2inchesinlenji 

 with its depth i 



most nothing it tk 

 commencement ; 

 but increasing pn> 

 gressively as k 

 chisel is made fe 

 penetrate towaii 

 the bottom of fc 

 first cut, as is it 

 presented at A. The object of this notch is to stop 1 

 small portion of the ascending sap, in order that it n» 

 be absorbed by the scion. In putting on the latter, w 

 place it as directed in the preceding 'case. Trantki 

 from the French of D'Albret. 



RESEARCHES ON VEGETATION. 



(By MM. Cloez and Gratiolet.) 



Although we have been occupied in researches! 

 vegetation for upwards of three years, we refraM 

 from publishing our results, until they should hare t 

 tained the greatest degree of accuracy and extent fi 

 which they were susceptible. The late publication i 

 M. Ville compels us, however, to make them know, 

 and to state that we have been endeavouring b 

 solve the same question as this gentleman, although ^ 

 a different method. Our experiments were mad<MJ 

 M. ChevreuPs laboratory, in 'the Museum of NatB» 

 History, and under his auspices. Our principle* 

 elusions have been laid before M. Decaisne, and to* 

 been, to a certain extent, already made public, as ttej 

 were incorporated by M. Fre'my in the lectures gn* 

 by him at the Museum last spring. ., » 



We do not intend to state in this place the deW* 

 our experiments ; they will be explained at leD S^ 

 work which we are preparing for the press ; we *f? 

 lay before the academy such of our results as &* 

 us to be certain and correct. . t^ 



It has long been known that the green part ot PJ 

 decomposes carbonic acid gas, and separates the oxtp 

 from it. This process is performed with great rapj 

 by submerged aquatic plants, and they separate 

 oxygen in a given time than most other P 1 * 11 ^ 

 fact induced us to select for our experiments w* 

 species of Potamogeton, Ceratophyllum, MynVlW" 

 and Conferva. 



Our conclusions may be stated thus : ^a 



1. Influence of Light.— Oxygen is disengaged ^ 

 in solar light, insensibly in diffused light, and not 



in darkness. In the latter case, no carbonic aci , 

 ever is given off by plants ; the contrary is g e 

 supposed. . jjjg. 



w 3 endeavoured to discover the comparative^ 



Of Coloured gla68 Oil the decomposition w |J ^ 



acid by the green parts of plants ; as well as i*^ 

 ascertain decomposition is most rapid under coi ^ 

 unpolished glass, then comes yellow glass, the n_ ^ 

 less transparent glass, then red, green, and "J?-^* 

 glass. We satisfied ourselves that these <" n 

 were not caused by differences of temperature. , j 



2. Influence of Temperature .—The deeoinp ^ 

 carbonic acid gas by aquatic plants exposed w * ^ 

 a temperature raised gradually from 39-2 *•.#'* 

 commence until the temperature is 59° F., ana ^ 

 maximum at 86° F. The decomposition oi * ^ 

 gas by plants exposed to liffht in a tempera*^ 



ence 



