(Sulphobenzamide may be derived from the quadruple type H2 O

2(H3 N)

by

the substitution of the tetratomic radicle (CH)iv for H and the biatomic

of chloride of phosphorus upon it is to replace the H2O of the type by HCl ; the product of this action may be written

HCN

(K) The formation of aldehydes from their corresponding acids by distilling their alkaline salts mixed with an alkaline formate *; e. g.—

(L) The substitution of hydrogen for compound radicles contained in organic basest; e.g.

(A) The combination of carbonic anhydride with the compounds of the alcohol radicles with alkali-metals; e. g.

* Piria, Ann. Chim. Phys. [3] xlviii. 113; Ann. Chem. Pharm. c. 104; Limpricht, Ann. Chem. Pharm. xcvii. 368; Ann. Chim. Phys. [3] xlviii. 118.

+ Matthiessen, Proc. Roy. Soc. ix. 118, 635.

‡ Wanklyn, Ann. Chem. Pharm. cvii. 125; cxi. 234; Ann. Chim. Phys. [3] liii. 42. The above reaction corresponds closely with that of sulphurous anhydride on zinc-methyl:

CH3 Zn +SO2
Zinc-methyl.

= CH3 Zn SO2.
Methylodithionate of zinc.

Hobson, Chem. Soc. Quart. Journ. x. 243; Ann. Chem. Pharm. evi. 287.

(B) The supposed formation of methyl compounds from acetone*; e.g.—

(C) The formation of complex hydrocarbons (ethylene, propylene, amylene, benzine, naphtaline, &c., by the action of heat on organic substances of simpler constitution. Synthesis of organic compounds)†.

III. Isologous transformations.

(A) The conversion of glycerine into iodopropylene, and of the latter into allylic alcohol‡:

(B) The production of cinnamic aldehyde from acetic and benzoic aldehydes §:

C2 H1O+CH®O=C° H®O+H20
Acetic alde- Benzoic Cinnamic

hyde. aldehyde. aldehyde.

(C) The production of cinnamic acid from chloride of acetyl and benzoic aldehyde || :

C2 H3OCI+C H° O=C° HO2+HCI.
Chloracetyl. Benzoic Cinnamic

aldehyde.

acid.

Throughout the foregoing Report Gerhardt's atomic weights have been used without discussion; for it seemed superfluous to enumerate once more the reasons for adopting them, which, as the science advances, become more and more numerous and conclusive. It may, however, be expected that some notice should be taken of such objections as have been recently made against this system.

Within the last few years three different chemists have, for very different reasons, proposed to modify Gerhardt's atomic weights, but they all agree in adopting the doubled atomic weight of carbon, while they reject the doubled

Friedel, Ann. Chem. Pharm. cvii. 174; cviii. 388.

+ Berthelot, Ann. Chim. Phys. [3] liii. 69.

Hofmann and Cahours, Chem. Soc. Quart. Journ. x. 316; Ann. Chem. Pharm. cii. 285; Ann. Chim. Phys. [3] 1. 432.

§ Chiozza, Ann. Chem. Pharm. xcvii. 350.

Bertagnini, Ann. Chim. Phys. [3] xlix. 376.

¶Some recent experiments nevertheless tend to show that the atomic weights assigned by Gerhardt to some of the metals ought to be doubled. For instance, the vapour-density of zinc-ethyl (Frankland, Ann. Chem. Pharm. xcv.), the way in which zinc combines with iodide of ethyl (similar to the combination of oxygen with zinc-ethyl, Zn2+C2 HI= C2 H$ Zn2 I, and O+C2 H5 Zn = C2 HO Zn), the vapour-density of mercury-methyl and of mercury-ethyl (Buckton, Proc. Roy. Soc. ix. 92, 311), and the combination of mercury with iodide of ethyl (forming C2 H5 Hg21), seem to show that the atomic weights of zinc and mercury are twice as great as they were adopted by Gerhardt. Similar reasons may be urged in favour of doubling the atomic weight of tin, as recommended some time since by Ŏdling (Phil. Mag. [4] xiii. 434). As these points, however, belong to inorganic chemistry, we cannot do more than simply refer to them here.

atomic weight of oxygen: we refer to Limpricht*, Kolbe†, and Couper‡. The first of these chemists founds his objection to the greater atomic weight of oxygen upon the fact that some salts crystallize with a quantity of water containing an odd multiple of 8 parts of oxygen. To this it may be answered, that the function of water in crystallized salts is not sufficiently well understood to warrant our drawing conclusions of any importance from the quantity of it contained in any particular substance, and that no reason has yet been shown why several atoms of a salt should not crystallize with one atom of water, as well as several atoms of water with one atom of a salt. The objections of Kolbe are founded on more general considerations. By comparing the composition of the so-called organo-metallic bodies with that of the inorganic compounds of the metals which they contain, he came to the conclusion that the metallic oxides are typical of the compounds of the metals with organic radicles.

For instance, taking the atomic weight of oxygen at 8, and writing oxide of zinc and arsenious anhydride ZnO and As O3 respectively, we get the following comparison of formulæ :

Oxide of zinc Zn O

Arsenious anhydride As O3

Zinc-ethyl .. Zn Et=Zn C2 H' | Oxide of arsenomo

nomethyl ...... As O Me = As OCH Oxide of kakodyl.. AsO Me2= As OC2 H® Termethylarsine.. As Me = As C3 H3.

Admitting the accuracy of such formula, it was natural to extend similar views to those compounds of carbon which do not contain metals. Accordingly, Kolbe regards carbonic anhydride CO', the highest known oxide of carbon, as the type of a large number of other carbon-compounds. Accord. ing to him, the replacement of 1 atom oxygen in carbonic anhydride by 1 atom hydrogen, or 1 atom of an alcohol-radicle, gives monobasic acids, such as those of the acetic and benzoic series; the like replacement of 2 atoms oxygen gives aldehydes and acetones; the replacement of 3 atoms oxygen gives ethers; and lastly, the replacement of all the oxygen gives alcohol-radicles and their hydrides. The following illustrations will make this clearer:—

It must certainly be considered fortunate for the interests of science that Professor Kolbe should himself have extended his theory to the purely organic compounds of carbon; for these being the precise substances of

* Limpricht, Grundriss der organischen Chemie (1855).

† Ann. Chem. Pharm. ci. 257. The same views were also advocated by Frankland in a lecture delivered at the Royal Institution, May 28th, 1858. (See Journ. Roy. Instit.) Ann. Chim. Phys. [3] liii. 469; Ann. Chem. Pharm. cx. 46.

which our knowledge is the most complete, the application of the theory to them makes it possible to arrive at a more certain conclusion as to its value, than would be the case were it confined to the substances to which it was originally applied. Respecting the above and similar formulæ, it may be observed,

1. That, leaving out of view the substances under discussion, there is no reason to believe that the oxygen in carbonic-anhydride can be divided into more than two parts; there is no evidence that carbonic anhydride contains more than two atoms of oxygen.

2. That there is no similarity, nor definite gradational difference of properties, between the type CO and the substances represented as deriving from it. 3. Two out of the four formulæ given above, namely the first and third, are in direct opposition to Gerhardt's atomic weights; we know, however, that they represent only half an atom of the bodies to which they are assigned.

Views respecting the nature of chemical affinity have induced Couper to adopt 8 as the atomic weight of oxygen. He, however, finds that, owing to a peculiar tendency which oxygen possesses to combine with oxygen, the smallest quantity of it which ever enters into combination is twice 8. This being admitted, it seems a matter of minor importance whether the smallest combining proportion of oxygen should be represented by the symbol O=16, or by the symbol O'=16.

September 10, 1859.

Report on the Growth of Plants in the Garden of the Royal Agricultural College, Cirencester. By JAMES BUCKMAN, F.S. A., F.L.S., F.G.S., &c., Professor of Natural History, Royal Agricultural College. THE following notes are upon experiments which have been completed or are still in progress in the experimental garden of the Royal Agricultural College, and this Report is furnished at the instance of the Natural History Section, the experiments having been made the subject of a grant from the funds of the British Association.

It is hoped that the present Report will show the desirability of continuing experiments upon plants, as whatever effect they may have upon our theoretical views, I think it will clearly be seen that many practical matters of great importance are involved in inquiries of this kind, and I shall therefore not detain the Section with any lengthened introduction, but at once ask for a kind and considerate attention to the following notes:

The cultivation of flax or lintseed offers such interesting matter to the naturalist, as being of importance in an economic and agricultural point of view, that we cannot help detailing some experiments connected therewith.

Plot A was sown in drills with a pure sample of linseed grown on the farm of the Royal Agricultural College.

Plot B was sown with a like weight of seed uncleaned, it therefore consisted of full half its weight of weed-seeds.

Plot C was sown with a like weight of pure seed as in plot A, to which was afterwards added a good sprinkling of dodder seed, viz. Cuscuta epilinum.

These beds were left unmolested, not even being weeded. The seed became ripe in the middle of August, at which time the following observations were noted upon each of them :

Hence, then, in as far as the economics of the question are concerned, we may safely conclude that the sowing of dirty flax-seed at any price is disadvantageous, and this not only that the resulting crop, if not quite ruined, is certain to be diminished in quantity and injured in quality, but, as ill weeds grow apace, all the sorts growing with the flax had sown much of their seeds before the flax-seed itself had ripened, so that a succession of weeds is by this means entailed upon the farm from generation to generation.

As regards the plot with dodder, the object of sowing these together was for the purpose of observing with my Class the manner in which the parasite became attached to its foster-parent, and I therefore offer the following remarks upon the growth of the Cuscuta epilinum, not as containing any new results, but as offering an example of the kind of experiments followed out in my botanical garden.

Fig. 1.

Fig. 2.

Fig. 3.

In about four days after the seed of the dodder was sown, a few whitish thread-like germs of about three lines in length were seen protruding from the soil, some of these being quite free, others crowned with the seed testa. Three days afterwards the flax came up, and the dodder might then have been seen, as in the accompanying fig. 1, bending its germ towards a flax-plant; by this time it has doubled in length; and if the flaxplant be far away, it seems to be endowed with the power of growing to as much as an inch in length in order to reach it, whilst in experiments of dodder seed sown by itself, the germs were always short and soon withered; but on inserting other plants in the same pot, they became attached to them, as Radish, Tomato, Groundsel, and

Chickweed were all in this way attacked by the dodder amongst which young plants were inserted; and in one case, where a pot of growing flax dodder was placed near a Sedum in my conservatory, the latter was attacked, and the dodder grew upon it most vigorously.

In a short time after the germination of the dodder and the flax, the