262 



THE GARDENERS' CHRONICLE. 



warm rain now, we should do." My reply always is, 

 "Your desired warm rain will soon end in cold rain, and 

 cold weather." — W. t Worcester. 



Miscellaneous.— Flora states that a plant of Abutilon 

 striatum has stood the winter in the Isle of Wight. It 

 ■was planted against a hothouse-wall, and was only occa- 

 sionally protected. A. C. informs us that he has tried 



quick-lime and cheese for preventing Vines from bleeding, 

 and says that "Drewen" is quite correct as regards its 

 efficacy. He remarks, however, that our correspondent 

 might have stated that it was the plan of the late Mr. 



Knight. A correspondent remarks that wasps are 



very early this season. He states that he has already 

 seen four ; the first he observed was on the 15th of this 

 month. 



I 



Foreign Correspondence. 



Frankfort, March 10 — Some time since you had a 

 question as to the possibility of naturalising Fire-flies in 

 England. As far as climate is concerned, I think they 

 might stand the climate of London, as well as that of 

 Cassel, where I have seen them in the latter end of May. 

 1 suppose food is as great a controller of animal range as 

 climate — and that one cannot provide. Slugs are scarcely 

 known here — a great advantage in all gardening, and 

 especially in the cultivation of early bulbs : perhaps the 

 •very pure sandy soil which covers almost every stratum 

 in Germany, may be the cause. Our Flower Shows are 

 preparing, and promise well this year. Rintz's Bellero- 

 phon is one of the finest azaleas I ever saw, and he has 

 raised a hybrid Rhododendron campanulatum, which is 

 rery fine. The winter has been very severe, and snow 

 very deep, until the other day, over all Germany, except 

 this part.* 



Societies. 



ROYAL INSTITUTION. 



April 19— Mr. E. Solly delivered a very interesting 

 Lecture on the Chemistry of Vegetation, and its applica- 

 tion to Agriculture. He commenced by contrasting the 

 study of organic with that of inorganic Chemistry ; the 

 uncertain and changeable nature of organic substances was 

 compared with the more definite, fixed, and stable [cha- 

 racters of inorganic compounds, and the difficulties at- 

 tending the investigation of organic Chemistry were stated 

 to depend chiefly on the great facility with which the va- 

 rious organic substances change, and are modified in pro- 

 perties and composition by comparatively slight causes. 

 The composition of plants was next inquired into, and 

 the manner in which, by very simple processes, they may 

 be separated into what are called their proximate elements 

 "When a plant is macerated in water, so as to remove all 

 the soft or soluble portions, lignin or woody fibre is left ; 

 the water in which it has been macerated, deposits, on 

 "being allowed to stand, a portion of starch ; if after this 

 the liquid is boiled, a scum separates or coagulates, con- 

 sisting of albumen and gluten ; whilst there remains 

 in solution gum and sugar. He stated jthat, of these 

 six substances the bulk of plants was composed; for 

 though there existed hundreds of other vegetable sub- 

 stances differing in composition and properties, yet these 

 constituted but a small part of the mass of plants, the 

 great portion of them being composed of the six proximate 

 elements just adverted to. When the process of analysis 

 was carried still further, it was found that all these various 

 substances were formed by the combination of three or 

 four elements, united together in different proportions. 

 The analysis of organic matter resembled that of inorganic 

 compounds in the fact that each element was collected and 

 estimated in a state of combination ; thus, the quantity of 

 water and carbonic acid gas given off during the combus- 

 tion of any organic substance being known, it was easy to 

 calculate the proportion of oxygen, hydrogen, and carbon 

 which it contained. In this manner lignin, gum, sugar, 

 starch, and many other vegetable products, on analysis 

 were found to consist merely of oxygen, hydrogen, and 

 carbon ; whilst in the same way, gluten, albumen, and a 

 number of other organic compounds, were found to con- 

 tain, in addition to those three elements, nitrogen — the 

 quantity of that substance present being estimated by the 

 quantity of ammonia formed during combustion. Besides 

 these organic matters,however,all plants were known to con- 

 tain a small quantity of inorganic matter— substances which 

 remained as ashes when the plants were burnt, and which on 

 analysis were found to consist of various salts of the alka- 

 liesand earths, compoundscontainiog phosphorus, sulphur, 

 chlorine, &c. These being the elements of plants, the 

 next questions were, whence and how plants obtained 

 them ? The composition of the air and soil was then de- 

 scribed, and the probable sources of the food of plants 

 pointed out. Mr. Solly observed, the growth of a plant 

 could not be regarded as a mere chemical process ; several 

 powers were at work, which modified and controlled che- 

 mical affinity m a most remarkable manner. Foremost 

 amongst these powers was the vital action ; what this was 

 we were quite ignorant, for we only knew it through the 

 effects which it produced. The vitality of a plant or seed 

 might he dormant for years or centuries, and when all the 

 other conditions requisite to vegetation were present, the 

 plant would grow and feed itself; the conditions essential 

 to vegetation, or the excitement of vital energy were heat, 

 light, and perhaps also electricity. Plants could not grow,' 

 nor seeds germinate, at temperatures below the freezing 

 point of water ; a certain degree of warmth was essential • 

 light also was necessary to the process of decomposition 

 carried on in the organs of plants, whereby the elements 

 of organic matter are assimilated ; and lastly, though 

 yery little was as yet known on this part of the subject, 

 it was hardly possible to doubt that electricity was ac- 



tively concerned in these operations. Under the influ- 

 ence of these powers plants possessed the means of de- 

 composing water, carbonic acid, ammonia, and nitric acid, 

 recombining their elements in the various forms of or- 

 ganic matter ; and it had been concluded from numerous 

 experiments, that plants always absorbed or assimilated 

 these substances in combination, and never in a free or 

 uncombined state. Thus the nitrogen of the air, which 

 constitutes about four-fifths of its bulk, does not appear 

 to enter into the composition of plants, the nitrogen which 

 they contain being probably wholly derived from the 

 ammonia and nitric acid existing in the air and soil. 

 The lecturer then drew attention to the relation which 

 plants bear to animals, and the very important part which 

 the former perform in the economy of the creation. The 

 manner in which all animals, either directly or indirectly, 

 deiive their nourishment from plants was shown ; and the 

 perfect manner in which plants preserve the healthy and uni- 

 form composition of the atmosphere, by removing from it 

 all the noxious gases generated by therespiration of animals, 

 and the decomposition of organic substances was described. 

 Mr. Solly next proceeded to consider the operations of 

 the farm, and defined the object of the farmer to be the 

 production of the greatest amount of food at the least 

 possible cost. He contrasted the condition of natural 

 pastures or forests, with cultivated lands ; and described 

 the effects produced by the constant removal of inorganic 

 compounds from the soil, in the crops. If it was 

 attempted to cultivate Wheat year after year on the same 

 ground, it was found that the crops gradually deteriorated, 

 and hence various manures, and systems of rotation or 

 fallowing, had been adopted. By some it had been sup- 

 posed that plants excreted poisonous matters from their 

 roots, and that the presence of these excretions in the 

 soil, rendered it unfit for the cultivation of the same kind 

 of plant ; but that this was not the case was shown by 

 many facts, amongst others, by the circumstance that in 

 some soils Wheat had been successfully cultivated for many 

 years in succession ; it was now known that the real ob- 

 stacle to the constant cultivation of the same crop was, 

 that the soil gradually became exhausted of certain inor- 

 ganic substances essential to the growth of the plants, 

 and hence it would appear that if the substances 

 annually removed from the soil could be regularly restored 

 to it, there is no chemical reason -why a crop should not 

 be grown for any number of years in succession on the 

 same soil. The great question therefore was, How can 

 we restore to the soil those substances on which its ferti- 

 lity depends, and which plants remove ? Much, no doubt, 

 might be done by mechanical agency ; thorough drain- 

 ing and deep ploughing would greatly assist in keeping up 

 the fertility of the soil ;] but at the same time a great deal 

 also might be done by chemistry, and more especially in 

 the preservation and application of manure. The loss of 

 manure under the present system, was described as being 

 enormous, and deserving the most serious and careful 

 attention. The lecturer then enumerated some of the 

 most important of the many substances employed as 

 manure, dividing them into those which supplied the 

 elements of organic matter, and those which supplied inor- 

 ganic substances. In the former class the salts of ammonia 

 were, of course, prominent, and the properties of that 

 substance, and the mode of fixing it by acids, sulphate of 

 iron, gypsum, &c. were considered. In the second class 

 of manures, the value of those containing phosphoric acid, 

 such as bones, was insisted on ; and the value of phos- 

 phoric acid in a soluble state, as it exists in the excellent 

 manure of Mr. Lawes, pointed out. The use of soluble 

 silicates, and the manner in which silica is absorbed by 

 plants, was experimentally illustrated, by precipitating 

 silica from a solution of an alkaline silicate by a vegetable 

 acid. The alkaline nitrates and common salt were next 

 spoken of; and with regard to the latter, it was stated 

 that though decidedly a good manure under many circum- 

 stances, it was highly improbable that it could act as a 

 fixer of ammonia, because the results of its decomposition 

 by carbonate of ammonia, viz. muriate of ammonia and 

 carbonate of soda, are salts which, under ordinary 

 circumstances, cannot exist together in solution; they 

 decompose each other, common salt and carbonate 

 of ammonia being formed. Amongst the substances 

 which existed in many of the best manures was 

 sulphur, an element which was present in most plants, 

 and which was an essential constituent of those which 

 formed the food of animals. Mr. Solly stated that plants 

 in all probability absorbed a portion of the sulphur which 

 they contain, from the atmosphere; his own experiments 

 had convinced him, that so far from sulphuretted 

 hydrogen being poisonous to plants, on the contrary in 

 small quantity it was apparently beneficial, causing them 

 to grow with increased vigour and luxuriance. This part 

 of the subject derived additional interest from the probable 

 influence which sulphuretted hydrogen has on the health 

 of animals, and the connexion which exists between the 

 presence of that gas in the air, and contagion, with various 

 epidemic disorders. Mr. Solly then inquired into the 

 possibility of plants deriving inorganic matter from the 

 atmosphere ; he described experiments made on various 

 orchidaceous plants, which showed that they contained 

 precisely the same amount of inorganic matter whether 

 their roots grew in earth, or they were freely suspended in 

 the air. It was unfortunately the case that no ordinary 

 chemical tests would enable us to detect very minute 

 quantities of solid matter in the atmosphere, but little 

 doubt could exist that many solid substances were occa- 

 sionally suspended in the air. In illustration of this 

 subject some curious experiments were shown. On 

 burning a small quantity of a mixture of nitrate of soda 

 and charcoal, a cloud of vapour arose, which was made to 

 traverse a long tin pipe, and the existence of soda in the 

 air as it came out of the further end of the pipe shown 



[Apr. 2 Q 



by the effect which it produced^nVs^all^ITTT^ 

 blue colour of -which was immediate?, Lf* S'' ** 

 bright yellow. Mr. Solly stated Tat one J^ ,* * 

 bonate of soda thus distributed through a r „„m ° f cw " 

 1000 cubic feet of air might be found fo C ° nta,nin § 

 after, diffused through every part of it and \^\ how » 

 eluded that each cubic foot contained not more'th ^ 

 thousandth part of a grain of carbonate of soda • V he 

 the test flame employed to indicate its presencVL * 

 occupy more than the thousandth part of a cumW ■ V* 

 might be fairly said to indicate th? millionth ^r* 

 grain of carbonate of soda. By another experiment* 

 was shown that the steam arising from a tolerably 2* 

 boiling solution of carbonate of soda contained a . 

 notable quantity of that salt, its presence being m ll? A 

 by the effect it produced on the colour of flame TK 

 manner in which volatile substances confer volatilit* 

 otherwise fixed substances, was illustrated by the eva™ 

 ation of phosphoric acid in contact with muriate ofVml 

 monia, a small quantity of the acid rising in vapour «* 

 condensing in large white flocks when heated with sal' am 

 moniac, though when heated alone it was perfectly fixed" 

 Attention was next drawn to the enormous extent to 

 which artificial manures are frequently adulterated and 

 the frauds which are too often practised by dealers on un- 

 suspecting farmers. As a strong example of this Mr 

 Solly stated, that a short time since he had procured a 

 quantity of a saline manure from a manufacturer and 

 suspecting from ite appearance that it was impure, had 

 been led to analyse it; on examination, it teas found to 

 contain only three per cent] of the salt for which it was 

 sold, the remaining 97 parts being other substances. If 

 such thing's were done, it was not to be wondered at that 

 we frequently heard complaints from those who had em- 

 ployed artificial manures, and had found no benefit from 

 the use of them. Amongst the many subjects of interest 

 connected with the application of chemical manures few 

 have excited more attention than the steeping or manur- 

 ing of seeds. A number of curious experiments on this 

 subject were described by Lord Bacon two centuries ago. 

 He showed that seeds steeped in certain solutions germi- 

 nated more rapidly than those soaked in other solutions;, 

 and remarks, that it is a very curious subject, deserving 

 of further investigation. At the present time, this effect 

 is as little understood as it was in that of Lord Bacon, 

 nothing more being known than the effects first described 

 by him. Mr. Solly stated that a series of experiments in 

 elucidation of this subject had recently been commenced 

 at the gardens of the Horticultural Society ; and that very 

 remarkable differences were becoming apparent in the 

 effects produced by the various solutions employed. He 

 also described a curious series of experiments on the effect 

 produced by muriate of lime, in increasing the retentive 

 power of the soil for moisture, and suggested the possibility 

 of these experiments leading to useful results in the cul- 

 tivation of the Turnip crop, in which it is of the 

 greatest importance that the first growth of the plant 

 should be healthy and vigorous, so as to get quickly 

 through that period in which it is most liable to the 

 ravages of the fly. The last subject brought forward was 

 one of considerable interest, and involving speculations of 

 a very singular nature. Mr. Solly drew attention to the 

 remarkable fact that the fossil bones of extinct animals 

 contain a considerable quantity of Fluoride of calcium J 

 thus the bones of the Colossochelys or great tortoise dis- 

 covered in the Himalaya Mountains by Messrs. Falconer 

 and Cautley, contain 11 per cent, of fluoride of calcium; 

 whilst recent bones on the other hand are found to con- 

 tain little or no fluoride of calcium. It is reasonable to 

 suppose that the earthy matter constituting the bones of 

 these extinct animals, was originally derived from plants, 

 and hence the question became one of interest— Whence 

 comes this fluoride ? It might be supposed that the fluoride 

 had passed into the substance of the bone by some sub- 

 sequent process. It might be supposed that the plant! 

 on which the animals fed contained fluoride of calcium, 

 or lastly, it might possibly be, that some ; nearer relation 

 existed between phosphorus and fluorine than we were ye 

 acquainted with ; and it was not impossible that toe 

 one might be converted into the other : this _ was m e ° 

 tioned merely as a curious speculation— possible, tnoug 

 perhaps not probable. In the meantime it was interes inj 

 to observe the action of fluoride of calcium in grow. 5 

 plants ; and accordingly experiments had been lnstitu , 

 the result of which as far as they could be ascertain* « 

 this early period, seemed to favour the conclusion tn« 

 fluoride was absorbed, and therefore that it mign P 

 sibly, to some extent, supply the place of P 00 ^^ 

 lime in plants. Mr. Solly concluded w,th * ome .% an d 

 remarks on the progress of Agricultural Chemistry, ^ 



the probable results of its future study, ex P re ^ ed , at e 

 regret that many are so sanguine as to the im ^ 

 benefits to be derived from it, that they can hardly 

 be disappointed by the results. t -ttttRAI* 



ROYAL SOUTH LONDON FLORlCbLiu** 



SO CI ETY. « 



April 23.-This, the first Show for the season, ^ 

 held in the Horns Tavern, Kennington. A "" £„ ,ras 

 superior to the last spring meeting, the exn ia , en s. 

 distinguished by a large number of well grown s\ ' ~ 

 Among the Miscellaneous Collections, by gentieme ^^ 

 that shown by Mr. Atlee contained some fine pian^^ 

 which was a very large specimen of Cytisus t 



covered with bloom, a Purple Rhododendron « i ^ 

 beauty, a well-grown plant of Boronia den J^ u the safl »e 

 a fine showy specimen of Acacia armata. * ^folii 

 collection were also Cornea speciosa, Polygal* IP inDgtI 

 in good condition, Kennedya coccinea, boron f Eric* 

 and other plants, including a fine J^ 1 ?*" ^d- 

 Wiiimoreana ; for these, a large Silver Medal w i ^ 











AUnutt 



