By way of commencement, then, let everybody that has sufficient leisure set to work, and rear as many silkworms, of the above-named species, as he possibly can; and if the process be not remunerative in a pecuniary sense, it most a.s.suredly will be in the amount of pleasure and knowledge obtained.

One caution I must give to those who cultivate _Bombyx mori_. Although _Yamamai_ requires sprinkled branches, _Bombyx mori_ does not; nor must the leaves be furnished to them while wet with rain or dew.

EFFECT OF COLD UPON IRON.--The article upon this subject, giving experiments of Fairbairn and others, referred to in our editorial upon the same subject, in our last issue, was crowded out by press of matter. The reader will find it in the present number.

UNIVERSAL BORING MACHINE.

Our readers will recollect an ill.u.s.trated description of an universal wood-working machine, published on page 79, Vol. XIII. of the SCIENTIFIC AMERICAN. The machine herewith ill.u.s.trated is manufactured by the same firm, and is a valuable addition to the many excellent wood-working machines now in use. A boring machine, though one of the simplest, is by no means an unimportant adjunct to a full outfit of wood-working machines. The one shown in our engraving is one of the most complete ever brought to our notice, and the great variety of work it is capable of performing, renders the name chosen for it peculiarly applicable. It is called the "Universal Boring Machine"

because the most prominent feature of its construction is its power to bore a hole in any desired angle with the axis of the bit.

Any sized bit required is inserted into the chuck, which is adjustable to fit large and small shanks. The mandrel which carries the chuck is made to traverse by a foot lever, so as to bore any depth up to twelve inches. The mandrel is driven by belt from a cone pulley of three faces, which gives the proper speeds for different sized bits.

Slots and stops upon the table enable the work to be set at any desired angle on the horizontal plane, while the table can be set on an incline to any angle not exceeding forty-five degrees. The table is twenty-one inches wide, with fifteen inches slide, and it can be raised or lowered fifteen inches.

The countershaft rests in self-adjusting boxes, and has a tight and a loose pulley eight inches in diameter. The traversing mandrel is of the best quality of steel, and the machine is otherwise made of iron in a substantial manner.

[Ill.u.s.tration: McBETH, BENTEL, & MARGEDANT'S UNIVERSAL BORING MACHINE.]

The several adjustments enable the operator to do all kinds of light and heavy boring, with ease and with great rapidity.

This machine was awarded the first premium at the Cincinnati Industrial Exposition, in October, 1870, and was patented through the Scientific American Patent Agency, Aug. 16, 1870. It is manufactured by McBeth, Bentel and Margedant, of Hamilton, Ohio, whom address for machines rights to manufacture, or other information.

COMBINED TRUNK AND ROCKING CHAIR.

A unique invention, calculated to increase the comforts of travellers on steamboats, ships, and in crowded rooms of hotels, is ill.u.s.trated in the engraving published herewith. It is the invention of T. Nye, of Westbrook, Me., and was patented by him, June 18, 1867. It is a combined trunk and rocking chair. The rockers are made to fold into recesses, where they are retained by suitable appliances till wanted.

The trunk being opened, as shown, forms a back to the seat, which is held by metallic braces. When closed, the whole presents the appearance of an ordinary trunk.

[Ill.u.s.tration]

COSMETICS.

The extensive use of preparations for hiding nature's bloom on the human countenance, and presenting to our view a sort of metallic plaster, suggests the inquiry, "how are these pigments made?" Without going into an unnecessary a.n.a.lysis of the "Bloom of Youth," the "Rejuvenator," the "Corpse Decorator," or the other inventions for destroying the skin, with which the druggists' stores abound, we may state again the fact, always unheeded, that all the detestable compounds are injurious. They are nearly all metallic poisons, and, if there be any that are innocent of this charge, they are in every instance harmful to the health. The color and surface of the skin cannot be changed by any application which does not close the pores; the pores, which are so exquisitely fine that there are millions of them to the square inch, and which must be kept open if a healthy and cleanly body is to be preserved. There is more breathing done through the pores of a healthy person than through the lungs; and we need not remind our readers of a ghastly piece of cruelty once enacted in Paris (that of gilding the body of a child, for a triumphal procession, which killed the subject in two hours), to show that the stoppage, in any degree, of the natural functions of so important an organ as the skin, is injurious. The immediate effect of the use of such compounds is to destroy the vitality of the skin, and to render it, in appearance, a piece of shriveled parchment. We must warn our readers that a temporary and meretricious "bloom" can only be attained at the cost of future freshness and lively appearance, so that a year or two of "looking like paint" is followed by a long period of "looking like dilapidation."

SMITH'S INFANT DINING CHAIR.

The accompanying engraving ill.u.s.trates a convenient and cheap infant dining chair, which can be attached to any of the ordinary chairs in common use.

[Ill.u.s.tration]

It consists of a chair without legs, suspended by the posts of the back, as shown, on pins engaging with hooked bars, which are placed upon the back of an ordinary chair. The details of the device will be seen by a glance at the engraving. The chair is adjusted in hight by placing the pins in the proper holes in the posts made for this purpose.

For further information, address Smith, Hollenbeck & Co., Toledo, Ohio.

THE MEDICINES OF THE ANCIENTS.

At the recent commencement of the Homeopathic College in this city, Mr. S. H. Wales, of the SCIENTIFIC AMERICAN addressed the graduating cla.s.s, and from his remarks, we quote the following:

"Many writers of our time persist in regarding this, above all others, as the best period in the history of our race; and, doubtless, it is true in many important respects. But I cannot forbear the suggestion at this moment that there was a time in the history of the world when the science of medicine was unknown, when people lived to the incredible age of many centuries; and, even after the span of life had been reduced to threescore and ten, sickness was comparatively unknown. In ancient times, it was looked upon as a calamity, that had overtaken a tribe or people, when one of its members prematurely sickened and died.

"Other arts and sciences flourished in Rome long before medicine was thought of; and the historian tells us that the first doctor who settled in Rome, some two hundred years before Christ, was banished on account of his poor success and the very severe treatment applied to his patients; and it was a hundred years before the next one came. He rose to great popularity, simply because he allowed his patients to drink all the wine they wanted, and to eat their favorite dishes.

Some writer on hygiene has made the statement that the whole code of medical ethics presented by Moses consisted simply in bathing, purification, and diet. This simplicity of life was not confined to the wandering tribes who settled in the land of Canaan, but was the universal custom of all nations of which history gives us any account.

This simple arrangement for health was considered enough in those primitive times, when the human system had not been worn out and exhausted by depletive medicines. The luxuries of public baths, athletic sports and games were deemed ample, both to educate the physical perceptions and to prevent disease.

"All this wisdom, which had its origin in ancient games and sports of the field, led to the erection of extensive bath-houses, and the adoption of other healthful luxuries to which all the people could resort to recreate their wasted powers."

BARNES' VENTILATOR FOR MATTRESSES, ETC.

Many diseases are caused by the use of beds not properly aired; and it is difficult, if not impossible, to properly air, or ventilate, a mattress, made in the usual manner. If this could be done more thoroughly than it generally is, much sickness would be avoided.

[Ill.u.s.tration]