in appearance, at least, by a double set of artificial teeth.

Dr. Mears found that the jaws were united on the left side with a firm band, fibrous or osseous, and that only a slight lateral movement existed at the articulation; there was also defective development of the bones of the left side of the face. The cicatrix on the cheek had contracted so as to draw away the lower lid and produce extensive ectropion; and the cornea had become opaque, either from the original injury or from exposure, so that the function of this eye was destroyed. The operation was completed at one sitting. A plastic operation was performed, to relieve the ectropion; and, in order to prevent unnecessary disfigurement, instead of making the usual line of incision to resect the jaw bone, the knife was then carried through the cicatrix directly outward toward the lobe of the ear; the ascending ramus of the jaw bone was then divided with the saw, just below the coronoid process, and the portion of the bone above this was removed from its socket. A chain saw was then introduced into the mouth and the vicious band of union was divided, giving at once considerable motion to the jaw. A number of defective teeth roots and stumps were removed, twenty-two in all; six teeth in front and on the right side were found to be good, and were allowed to remain. When seen six or seven weeks after the operation, the wound had healed, except a small superficial spot. The ectropion had been corrected; she was able to completely cover the eye with the lids. The jaw could be opened over an inch, and admitted lateral motion for chewing. She is now being fitted with artificial teeth; her appearance has been immensely improved. Before the operation she was obliged to constantly wear a black patch over her eye, which is no longer necessary; a veil is worn when she is out on the street, which sufficiently hides the cicatrix.-College and Clinical Record.

ZINC VERSUS BABBITT METAL.

We

Thirty years ago a partner of mine, Dr. D. H. Goodno, after experimenting with all the metals ever used for dental dies, and finding nothing satisfactory, at last thought that " Babbitt metal," then but little known, might answer the purpose. He tried it, and found, to his great relief, that it was just what he needed. adopted it at once, and after having used it exclusively all these years, can say it is a perfect thing for the purpose. And why should it not be? It has all the requirements needed, viz.: non-shrinkage, hardness, toughness, smoothness, and melting at a low temperature. Now, while zinc is hard, its shrinkage is a serious objection. Type metal does not shrink, but is too brittle.

But it is necessary that the Babbitt metal should be made from a correct formula. Much that is sold, while it answers the purpose for which it is generally used, viz., bearings for machinery, is made in such a manner that it costs less than forty cents per pound, will not answer, for it can't be made and sold for less.

To ensure a good article make it yourself, as follows: Copper, I part; antimony, 2 parts; tin, 8 parts. Melt in a crucible in the order named, turning off as soon as the tin is dropped in, and remelt. The S. S. White Company is now making the above formula. For counter die, use seven parts lead and one part tin, and don't turn too hot; coat the die with whiting. For convenience, moisten the sand with sweet oil, as it is then always ready for use, and there will be no danger of your cast being spoiled from excess of moisture.

I seldom make the second die, even in sharp, irregular lower cases. The plate will always fit the plaster model, and if that is correct will, of course, fit the It is time that zinc was banished mouth. from dental laboratories, books of in

SEC. 1. Be it enacted by the Senate and House of Representatives of the Commonwealth of Pennsylvania, in General Assembly met, and it is hereby enacted by the authority of the same : That it shall be the duty of any person practicing dentistry within this commonwealth within three months after the passage of this act, and of any person intending to practice dentistry within this commonwealth, before commencing the same, to have recorded in the recorder's office in the county in which he or she practices or intends to practice, the diploma or certificate provided for in the act to which this supplemented.

SEC. 2. Any person beginning to practice dentistry in this state after the passage of this act, having a dental diploma issued or purporting to have been issued by any college, university, society or association, shall present the same to the State Examining Board provided in the

act to which this is a supplement, for approval; such examining board being satisfied as to the qualifications of the applicant and the genuineness of the diploma shall, without fee, indorse the same as approved, after which the same may be recorded as aforesaid.

SEC. 3. Any person who is entitled to practice dentistry in this commonwealth without a diploma or certificate under the provisions of the eighth section of the act to which this is a supplement, shall make written affidavit before some person qualified to administer an oath setting forth the time of his continuous practice, and the place or places where such practice was pursued in this commonwealth, and shall within three months after the passage of this act have such affidavit recorded in the recorder's office of the county in which he is practicing, and it shall be the duty of the recorder to record such diplomas, certificates, and affidavits, in a book provided for such purpose.

SEC. 4. Any person who shall violate or fail to comply with any of the provisions of this act or the act to which this is a supplement, or who shall cause to be recorded any diploma or certificate which has been obtained fraudulently, or is in whole or in part a forgery, or shall make affidavit to any false statement to be recorded as aforesaid, shall be guilty of a misdemeanor, and on conviction shall be sentenced to pay a fine of not less than fifty nor more than two hundred dollars for each offence for the use of the proper county.

SEC. 5. All acts or parts of acts inconsistent herewith are hereby repealed.

THE air, the atmosphere we breathe, is composed of four parts of nitrogen gas and one part of oxygen. For example, if we mix four gallons of nitrogen and one of oxygen, we have five gallons of air. It is the oxygen that supports life; the nitrogen is simply to dilute it.

THE new officers of the American Dental Association for the ensuing year are as follows:

President, Dr. E. T. Darby, Phila.; 1st Vice President, Dr. C. S. Stockton, N. J.; 2d Vice President, Dr. T. S. Moore, S. C.; Secretary, Dr. G. H. Cushing, Chicago; Cor. Secretary, Dr. Harlan, Chicago; Treasurer, Dr. G. W. Keeley, Ohio; Examining Committee, Dr. Friedichs, La.; Dr. Morrison, Mo.; Dr. Perry, N. Y.

The next meeting will be held at Saratoga Springs, N. Y.

THE officers elected for the Pennsylvania State Dental Society for the ensuing year were: President, Dr. S. H. Guilford, Phila.; 1st Vice President, Dr. Elliott, Meadville; 2d Vice President, Dr. Jas. Truman, Phila.; Rec. Secretary, Dr. Kramer, Lebanon; Cor. Secretary, Dr. Fundenburg, Pittsburg; Assistant Secretary, Dr. Miller, Altoona; New Members of Examining Board, Drs. Green and Magill.

The next meeting will be held at Wilkesbarre, Pa.

THE thirteenth annual meeting of the New Jersey State Dental Society opened its session at the Coleman House, Asbury Park, Wednesday, July 18th, and continued three days. The annual address was delivered by the President, Dr. J. Y. Palmer. He spoke in part as follows:

"It is with great pleasure that I greet you on the occasion of our 13th annual assembling, as a society devoted to the

For the

first time since 1877, we have changed our place of meeting.

"A bill authorizing this society to confer the degree of M.D.S. was urged before the last Legislature of this State, by a committee appointed for that purpose.

"Let us pause a moment to speak a word concerning the loss of him whom the entire profession in the east had learned to think of whenever the electric mallet was mentioned. I refer to Dr. Marshall B. Webb, of Pennsylvania. was an ardent, enthusiastic young man, stricken down in the prime of life; but not until he had accomplished much in his chosen profession.

He

"Esthetic Dentistry," by Dr. E. Harvey Bunting.

"The Legal and Moral Responsibility of Dentists in the Administration of Nitrous Oxide Gas," by Dr. J. Allen

Osman.

"Lobilia Inflata as a Therapeutic Remedy," by Dr. J. W. Scarborough; and two volunteer essays by Drs. Brown and Scarborough.

Out of the eight candidates for admission to practice dentistry in the State only three were successful.

The following officers were elected for the ensuing year :

President, E. H. Bunting, Sr.; Vice President, J. W. Scarborough; Secretary, Chas. M. Meeker; Treasurer, George C. Brown; Examining Board, Fred. C. Barlow, Jersey City; F. A Levy, Orange; J. Hayhurst, Lambertville; Charles W. Meloney, Camden; Jas. Y. Palmer, New Brunswick.

below 32° Fahr. water exists in the solid state, and is known as ice.

According to Prof. Rankine, ice at 32° has a specific gravity of 92. Thus a cubic foot of ice weighs 57.45 pounds.

When water passes from the solid to the liquid state heat is required for liquefaction, sufficient to elevate the temperature of one pound 143° Fahr. This is termed the latent heat of liquefaction. According to Mr. Person, the specific heat of ice is 504, and the latent heat of liquefaction 142.65.

From 32° to 39° the density of water increases; above the latter temperature the density diminishes.

Water is said to be its maximum density at 39° Fahr.; and under pressure of one atmosphere weighs, according to Berzelius, 62.382 pounds per cubic foot.

Water is said to vaporize at 212° Fahr., and pressure of one atmosphere (14.7 pounds), but Faraday has shown that va

They adjourned to meet at the same place next year.

THE PROPERTIES OF WATER.

Water was supposed to be an element until Priestly, late in the eighteenth century, discovered that when hydrogen was burned in a glass tube water was deposited on the sides. (It has been shown that the combustion of hydrogen requires eight parts by weight of oxygen, and vapor of water is the result.)

It was not, however, until Cavendish and Levoiser investigated water that its chemical composition was determined.

The several conditions of water are usually stated as the solid, the liquid and the gaseous.

Two conditions are covered

by the last term, and water should be understood as capable of existing in four different conditions-the solid, the liquid, the vaporous and the gaseous. At and

absolute zero, and that the limit to vaporization is the disappearance of heat.

Dalton obtained the following experimental results on evaporation below the boiling temperature:

Dalton holds good only for dry air, and when the air contains vapor having an elastic force equal to that of the vapor of the water, the evaporation ceases. The boiling point of water depends upon the pressure. Thus, at one atmosphere (14.7 pounds) 29.22 barometer the temperature of ebullition is 212°. With a partial

vacuum, or absolute pressure of one pound (2.037 of mercury) the boiling point is 101.40 Fahr.

Upon the other hand, if the pressure be 74.7 pounds absolute (60 pounds by the gauge), the temperature of evaporation becomes 307° Fahr.

The relations of temperatures and pressure have been made the subject of special investigation from the time of Watt, down to the celebrated experiments of Regnault, which have been accepted as conclusive so far as they extend.

The relations of pressure and density, however, have not been determined by experiment. Messrs. Fairbairn and Tate have investigated this problem and deduced a formula, but late experience has shown that while the Fairbairn and Tate formula is perhaps the best of its kind, it can not be accepted as correctly stating the relations of pressure and density. The vaporous condition of water is limited to saturation. That is to say, when water has been furnished with latent heat sufficient to render it anhydrous, the vaporous condition ends, and the gaseous state begins. Super-heated steam is water in the gaseous state. The temperature of the gaseous state of water, like that of the vaporous, depends upon the imposed pressure. Under pressure of one atmosphere, water exists in the solid state at and below 32° Fahr.; from 32° to 212° it exists in the liquid state; at and above 212° in the vaporous state. It has been stated that water boils at 212°, but M. Magmus and Donney have shown that, when water is freed of air, it may be ele

BEDFORD, IND., July 30, 1883. ED. DENTAL PRACTITIONER:- -In your journal for July, W. R. Hall, says: "I do not believe mercury, per se., absorbed into the system through the mucous membrane, does the gums any harm.” In the PRACTITIONER for April, he said he had seen cases of sore mouth from absorption of mercury from rubber plates. I think he will find it as difficult to reconcile these two statements, as to demonstrate that mercury is absorbed by the mucous membrane from rubber plates, which I asked him to do. The trick of burning the rubber and collecting the mercury is an old one, and does not prove anything as to what takes place in the mouth. When rubber plates dissolve in the mouth, then we may look for free mercury, but nobody has been able to find it yet, and when asked to demonstrate that it can be found in the mouth, the request is met as above. Hence, I repeat, let those who make such assertions prove them correct, or acknowledge they can not do it. During the past year, I have seen as sore gums