There is not one sentence in this little essay which may not be justly set down as mere commonplace. We acknowledge the fault; but defend it on the ground that sound and useful commonplaces require a continual refreshing and re-presentment, so many persons being, after all, unaware or forgetful of them.
On a similar ground of defence, we would take leave to remind mankind of the good old maxim, 'Hear the other party.' Familiar to most people, observed by some, there are multitudes who uniformly act as if they had never heard of it. To be quite candid, we often catch ourselves neglecting it; and always, at the best, it takes a struggle to make it a reality in our conduct. Experience, however, impresses us more and more with a sense of its being absolutely essential to the ascertainment of truth in any disputable case. There is so much bias from self-love, so much recklessness about truth in general, and so much of even a sincere faithlessness of narration, that no partial account of anything is to be trusted. It is but a small concession to the cause of truth, to wait till we hear the statement of the opposite party, or not to pronounce without it. If anything were required to prove how little this is reflected on, it would be the readiness of nearly all persons to tell their own story, without intimating the slightest doubt that it is to be implicitly received on their own shewing. One cannot walk along a street, but some friend will come up and inflict a narration, limited entirely to his own view of a case in which he is interested or aggrieved, practically ignoring that there can and must be another way of stating it. And so great is the complaisance of mankind, that no one thinks of intimating any necessity for consulting another authority before giving judgment. Here the vicious habit of thoughtless pronouncing is doubly bad, as it involves also a kind
of flattery.
There are some novel doctrines and theories, which seem doomed to meet with prejudice and opposition, but which yet must have some vitality about them, seeing that they survive so much ill-treatment. It is curious to observe how little regard to the rules of reasoning is usually felt to be necessary in opposing these theorieshow mere pronouncing comes to stand in their case in the stead of evidence and argument. Although they may have been brought forward as mere forms of possible truthideal points round which to rally the scattered forces of investigationand only advanced as far as facts would go, and no furtheryou will find them denounced as visions, tending to the breach of the philosophic peace; while, on the other hand, those who oppose them, albeit on no sort of ground but a mere pronunciation of contrary opinion, obtain all the credit due to the genuine philosopher. Abstractly, it would be generally admitted that any doctrine for which a certain amount of evidence is shewn, can only be overthrown by a superior force of evidence on the other side. But practically this is of no avail. Doubt and denial are so important to philosophy, and confer such an air of superior wisdom, that merely to doubt and deny will be pretty sure to carry both the educated and the uneducated vulgar. To get a high character in that position is of course very easy. Little more than pronouncing is required. As to the respective positions of the affirmer and denier in some future time, when truth has attained the power of asserting her reign against prejudice, that is another thing.
To return to the general questionIf any one be impressed by our remarks with a sense of the absurdity of pronouncing without knowledge and reflection, let him endeavour to avoid it, and he will confer a sensible benefit on society. When next he is in company, and a subject occurs to tempt him into an expression of opinion, let him pause a moment, and say to himself: 'Now, do I know anything about itor if I know something, do I know enoughto enable me to speak without fear of being contradicted? Have I ever given it any serious reflection? Am I sure that I have an opinion about it at all? Am I sure that I entertain no prejudice on the point?' Were every one of us children of British freedom to take these precautions, there would be more power amongst us to pronounce wisely. There would be a more vigorous and healthful public opinion, and the amenity, as well as instructiveness of private society would be much increased.
COOLING THE AIR OF ROOMS IN HOT CLIMATES
The new process of cooling now to be described, is founded on a scientific principle, certain and satisfactory in its operation, provided it be reduced to practice in a simple manner. The discoverer is Professor Piazzi Smyth, who has presented a minute account of it in a paper in the Practical Mechanic's Journal for October 1850, and also separately in a pamphlet. We invite public attention to this curious but simple invention, of which we shall proceed to present a few principles from the pamphlet just referred to.
Mr Smyth first speaks of the uselessness of the punkah, and the danger of the wet mats. 'The wet mats in the windows for the wind to blow through, cannot be employed but when the air is dry as well as hot, and even then are most unhealthy, for although the air may feel dry to the skin, there is generally far more moisture in it than in our own climate; but the height of the temperature increasing the capacity of the air for moisture, makes that air at 80 degrees feel very dry, which at 40 degrees would be very damp. Now, one of the reasons of the lassitude felt in warm climates is, that the air expanding with the heat, while the lungs remain of the same capacity, they must take in a smaller quantity by weight , though the same by measure , of oxygen, the supporter of life; but if, in addition to the air being rarefied, it be also still further distended by the vapour of water being mixed with