stances, it is obvious, that the front varnish must adhere to that at the back all round the edges where they meet; and that the holes left in the edges of the painted canvas will serve to unite that to the coutchouc canvas at the back, as if it were by so many incorruptible tacks that cannot be removed. Thus is our painted canvas effectually enclosed in a transparent case, hermetically closed all round, without the pofsibility of having any air admitted to it either from behind or before, unless by tearing it with violence.

*

I have been at the pains to describe this procefs so minutely, chiefly with a view to show, that by a similar mode of procedure paintings in crayons, and those in water colours, whether opaque or transparent, each of which pofsefs certain excellencies peculiar to itself, may by a similar procedure be rendered at a small expence equally indestructible as those in oil, a desideratum that has been long and ardently looked for. We have met with no facts as yet that give us reason to suppose that coutchouc, when in its natural fluid state, acts chemically as a menstruum on colours that enter into the composition of any kind of paint. Neither do I know that it would adhere to paper, or the substance of water colours; but I am rather inclined to think it would not, and that it could be formed into a thin inadhesive film before them as a glafs; and that, of course, they might all be closed hermetically between two layers of it, without muchtrouble or expence, as above described.

After the same manner might be preserved for any length of time, without any abatement of their sharp

which drawings is well known; but, on account of the difficulty of preserving them, that manner of drawing has been reluctantly abandoned by every artist; so that its full powers may be said to be as yet, in a great measure, unknown. A path is thus opened to the exertions of genius that may be said to be untrodden by any one; and who will pretend to set bounds to the sublime effects which may thus be rapidly produced?

It is scarcely necefsary, after the above, farther to specify, that large prints, which do not admit of being glazed but at an enormous expence, may be thus most effectually secured even at a moderate charge.

I have been at the pains to give this glance at a few of the valuable uses that may be made of this singular production, with a view to imprefs the mind of the public, as early as pofsible, with a deep conviction of the importance of extending the cultivation of the plant that produces it, as soon as may be, in places that are well adapted for its growth. All these uses, however, it ought never to be forgotten, depend upon our being able to obtain the juice in its native state; for, after it has been once concreted, it never can be made to answer these purposes by any process that has been yet discovered. And, though Mr. Howison has found that the juice retains some of its native qualities for more than a year without any preparation, yet he fails not at the same time to remark that they were greatly weakened. Our distance from India is such as to bar us from the hope of ever being able to obtain the native juice from thence in a proper condition for use in such quantities as might be wanted. But should a

stances, it is obvious, that the front varnish must adhere to that at the back all round the edges where they meet; and that the holes left in the edges of the painted canvas will serve to unite that to the coutchouc canvas at the back, as if it were by so many incorruptible tacks that cannot be removed. Thus ist our painted canvas effectually enclosed in a transparent case, hermetically closed all round, without the pofsibility of having any air admitted to it either from behind or before, unlefs by tearing it with violence.

I have been at the pains to describe this procefs so minutely, chiefly with a view to show, that by a similar mode of procedure paintings in crayons, and those in water colours, whether opaque or transparent, each of which pofsefs certain excellencies peculiar to itself, may by a similar procedure be rendered at a small expence equally indestructible as those in oil, a desideratum that has been long and ardently looked for. We have met with no facts as yet that give us reason to suppose that coutchouc, when in its natural fluid state, acts chemically as a menstruum on colours that enter into the composition of any kind of paint. Neither do I know that it would adhere to paper, or the substance of water colours; but I am rather inclined to think it would not, and that it could be formed into a thin inadhesive film before them as a glafs; and that, of course, they might all be closed hermetically between two layers of it, without much trouble or expence, as above described.

After the same manner might be preserved for any length of time, without any abatement of their sharp

which drawings is well known; but, on account of the difficulty of preserving them, that manner of drawing has been reluctantly abandoned by every artist; so that its full powers may be said to be as yet, in a great measure, unknown. A path is thus opened to the exertions of genius that may be said to be untrodden by any one; and who will pretend to set bounds to the sublime effects which may thus be rapidly produced?

It is scarcely necefsary, after the above, farther to specify, that large prints, which do not admit of being glazed but at an enormous expence, may be thus most effectually secured even at a moderate charge.

I have been at the pains to give this glance at a few of the valuable uses that may be made of this singular production, with a view to imprefs the mind of the public, as early as pofsible, with a deep conviction of the importance of extending the cultivation of the plant that produces it, as soon as may be, in places that are well adapted for its growth. All these uses, however, it ought never to be forgotten, depend upon our being able to obtain the juice in its native state; for, after it has been once concreted, it never can be made to answer these purposes by any procefs that has been yet discovered. And, though Mr. Howison has found. that the juice retains some of its native qualities for more than a year without any preparation, yet he fails not at the same time to remark that they were greatly weakened. Our distance from India is such as to bar us from the hope of ever being able to obtain the native juice from thence in a proper condition for use in such quantities as might be wanted. But should a

time ever come, when a friendly intercourse shall be established between us and the natives in the northern parts of Africa, where this plant, in all probability, might be reared in abundance, as well as many others that would prove highly beneficial to us, we might then hope to be able to profit greatly by this valuable discovery. With a view to forward this improvement, I shall soon give a botanical account of the tree, as communicated by Dr. Roxburgh, with hints tending to facilitate its propagation, adding some useful experiments made by that gentleman upon the concrete juice, which will open the prospect of improvements of a kind different from the above, that our posterity may derive from this singular production of nature.

On Plagiary and Plagirists.

No one thing in the literary world excites such universal detestation as plagiarism; and, indeed, there is such a meannefs in the idea of one man endeavouring to avail himself of the talents of another for augmenting his wealth or his fame, that it is, perhaps, impossible to exprefs with sufficient energy the despicable contemptibleness of a being who is capable of deliberately engaging in such an attempt.

But in proportion to the degradation which such a character implies, ought our caution to be to avoid involving the innocent in the heavy opprobrium of such an imputation. We ought in no case, therefore, ever to admit the charge, until all the circumstances have been deliberately weighed, and fully proved upon the