1844.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



w 



PROFESSIONAL POLICY, 



Sir, — There is by far more truth than there ought to be — perhaps, 

 not quite so much as there might have been — in the reflections throvfn 

 out against architects, in page 123 of your last No. Taken as a body, 

 they do show themselves to be both too supine and too self-confiJent ; 

 and they seemingly take no other interest in their art, than what is 

 suggested by a concern for their own personal and immediate interests. 

 It would be folly to look for either among them or any other class of 

 persons, such Quixotic public spirit as would induce them to neglect 

 the latter for the former; still tliey might manifest something like a 

 disinterested affection for art for its own sake, — supposing they really 

 entertain any; or if they do not, they might, out of mere policy, assume 

 some appearance of liberality of feeling, and might also pay some 

 deference to public opinion. On the contrary, by doing nothing to- 

 wards the encouraging extra-professional study, they appear rather 

 desirous to check it, and to show themselves determined neither to 

 countenance, nor to pay any attention to what is done or said by any 

 section of the general public. 



Science can shift for itself, because its services cannot be dispensed 

 with; but art stands in a widely different position: it depends upon 

 public sympathy and favour, upon u general disposition to encourage 

 it, — which is likely, it may be presumed, to be in proportion as a taste 

 for art is generally diffused and cultivated. If they do not perceive 

 this, architects must be very obtuse ; if perceiving it, thry do nut 

 shape their course accordingly, they must be very disinterested — dis- 

 interested at least as far as their art is concerned. But what they do 

 not perceive or now shut their eyes to, they may ere long very sensi- 

 bly /ul. Indeed, they might have found out ere this some of the 

 consequences which are resulting from their own negligence and 

 supineness. By standing aloof, and refusing to take any share in the 

 task of enlightening the public on the subject of their art, architects 

 not only betray an unworthy jealousy, but by their own incominunica- 

 tiveness and silence, they actually surrender up to laymen and extra- 

 professional writers a very important influence — that derived from 

 the power of promulgating their opinions unchecked, and of guiding 

 public taste, whether in a right direction or a wrong one. And 

 though, individually, some of the writers of this class may be feeble 

 enough ; as a body they are not to be despised. 



If no one else, Mr. Gwilt is, perhaps, now fully sensible of this, be- 

 cause so far from awing — as he, no doubt, flattered himself he should 

 do — Reviewers, Amateurs, et hoc genus oiiuie, into silence, his sneers 

 and reproaches seem to have stirred up their blood, to have rendered 

 them more daring and active than ever. He lias certainly made 

 himself conspicuous by rendeciiig himself obnoxious, and a mark for 

 their shafts, some of which are likely to remain sticking in him ; 

 neither does the poor "stricken deer" meet with any show of sympathy 

 from the rest of the herd, whose maxim on such occasions is, sauve 

 qui pent. 



Another circumstance which does not say much for the con amore 

 feeling with which architects apply to their art, is that, notwithstand- 

 ing the extraordinarily great numerical increase of the profession, as 

 far as they are concerned there is less encourag(>ment than ever for 

 architectural publications. Were it not for purchasers of a difl'erent 

 class, there would scarcely be any sale at all for them. It is the same, 

 too, in regard to works of the same kind imported from the Continent: 

 not one copy in twenty — perhaps not even a single one, finds a pur- 

 chaser among professional men; it may thereture be questioned 

 whether the latter are even aware of the existence of many foreign 

 publications of the sort, unless they happen to have seen thein on the 

 library table of some amateur. It may be that those among the pro- 

 fession who can best afford to purchase expensive architectural books, 

 are those who least of all need them for any infurmation or instruction 

 to be derived from them. Still it might be presumed that whether 

 they have actual occasion for them or not, they would be glad to 

 possess them, just as they do pictures and other productions of art : 

 nay, even if only in evidence of their own art'ection for their own art, 

 and of their willingness to encourage it in every possible shape. But, 



pudet ha;c opprobia tantis 

 Et dici potuisse et non potuisse refelli, 



— such is not the case : some of those who can afford lo do most in 

 the way of bestowing such encouragement on architectural literature 

 and illustration, are precisely those who show themselves most nig- 

 gardly ; and that, sometimes to a degree quite incredible. Shocking 

 as It may be to say all this, it is still more shocking that there should 

 be any occasion for saying it at all ; and to think of suppressing it is 

 perfectly useless, because if it does not reach the public througli one 

 channel, it will through another, and the attempt to keep it back will 

 only cause it to burst forth at last with uU the greater violence. 



As to myself I own that I might honour professional men much 

 more than I now do, did I honour architecture much less. 



I remain, &c., 



Censor. 



AGRICULTURAL CHEMISTRY. 



By Professor Brande, F.R.S., &c. 



Lecture VI. — Delivered at the Royal Institution, March 3, 1844. 



(Specially reported for this Journal.) 



The great bulk of a vegetable consisting of carbon, hvdrogcn, oxyRen, and 

 nitrogen, the question arises, are these contained in the water, carbonic acid, 

 and ammonia of the air, and the table given of the compoiition of these 

 answers in the affirmative ; the carbon is in the carbonic acid, the hydro.;en 

 in the water and the ammonia, the oxygen in the water and the acid, and llie 

 nitrogen in the ammonia. But it may be said that there is carbon in the soil 

 as humus ; true, but not in a fit state to act as food for the plant, wdiich 

 would starve when surrounded with these four elements, if ihey were 

 not in a state of combination proper for its consumption. Carbon 

 is of no use to the plant without it be combined with oxygen as carbonic 

 acid, nor hydrogen without it be combined with oxygen as water, or with 

 nitrogen as ammonia, nornitrogen except, with hydrogen, it exists as am- 

 monia. These gases are all evolved during the decomposition of animals. In 

 a similar condition is man, for though hercijuires little else than the elements 

 they contain for his life and growth, yet it is of no use offering him, water, 

 carbonic acid, and ammonia as food ; for him these must be elaborated by the 

 plant into gum, starch, sugar, gluten, fibrin, 8cc. Thus it is seen that the 

 plant feeds upon unorganised matter, but organizing it, converting it into its 

 own tissues, it renders it into a proper condition to become the food of the 

 animal, which, in its turn, converts it into its own substance ; and then, to 

 complete the circle, when the animal dies, his decomposing body passes again 

 into those gases which are the proper food of plants. 



First, as regards the water. This is always present in the air in large 

 quantities as moisture, but is very variable, depending principally upon tem- 

 perature and pressure, the supply being always kept up by the evaporation 

 conlinually taking place. The greater the heat the greater the evaporaijon, 

 and the more water the air can take up. When the air has not, for its tem- 

 perature, the proper quantity of moisture, in passing over a field itdcprives 

 the crop of some of its water, by increasing too mucli the evaporation from 

 the surface of the leaf, and is called a parching wind. When, on the con- 

 trary, the air is very moist, plants take water from it. Capillary action lakes 

 place continually in the juices of a plant, and the evaporation at the surface 

 of the leaf, like that in the soil, causes the thin sap which rises into the leaf to 

 go out of it thick and syruppy. This will serve to explain why the leaf con- 

 tains so large a per centage of ash. 



When water is cooled down to a temperature of 40°, it begins to expand, 

 and continues expanding till, at 32°, it freezes. This expansion takes place 

 with gi^'antic power, rending asunder the hardest rocks into which water 

 has infiltered, .and bursting leaden and iron pipes with facility. Phials, and 

 (hick iron tubes, filled with water, may be heard to burst if immersed in an 

 artificial freezing mixture. In this manner the frost acts in disintegrating 

 the sell. In passing from the liquid to the solid state, water gives out heat 

 until it is solid, heat which was not previously sensible to the thermometer, 

 termed latent heat. This heat, wbiLli is always evolved when liquids Ix^come 

 solid, may be rendered evident by crystallizing a solution of a salt, such as 

 sulphate of soda. If a hot saturated solution uf this salt be corked up in a 

 Hask whilst steaming, the vapour condensing forms a partial v.acuum, and 

 the solution remains liquid ; but sn soon as the air is admitted, crystalliza- 

 tion takes place rapidly, beat is evolved, and owing to the expansion, the 

 liquid rises up the neck of the flask. This may be considered to represent 

 w hat takes place during the freezing of water. Water is useful also as a sol- 

 vent of air, as it will take up l-3Cth of its bulk. The air which rain or snow 

 contains has been found to have more oxygen than is in the atmosphere, as 

 though they had a greater .attraction for the oxygen than fur the nitrogen. 

 The proportion is increased from 21 to 32 per cent. It also has fri m one to six 

 per cent, of carbonic acid. Thus it supplies to the plant air of much more 

 favourable composition than the atmosphere. It also carries down with it a 

 portion of ammonia, which gives to it the feeling of softness. This is of use 

 to the plant, and though 1,U00 gallons of rain water is nothing to be evapo- 

 rated from a field, yet the amount of animoniacal salts left behind is by no 

 means trilling. 



As in the passage from the liquid to the solid, water gives out heat, so in 

 vapourising, or in the passage from the liquid to the gaseous state, water 

 abstracts heat. Wet cloths are irequcnlly wrapt round the head fur thi 

 purpose, the water evaporating .carries with it heat, which it renders latent, 

 taking it from any substance near it. It is essential for its cliange_of condi- 



