HINTS AND QUERIES.

Prize Offer.—The Verein Deutseher Zahnkiinstler (the Association of German Dentists) makes the following prize offer:

For the "invention of a process for preparing gold so that it may be manipulated for fillings after the manner of amalgam," we hereby offer a prize of owe thousand five hundred marks. The amount of 1500 marks is deposited in the Sachischer Bank, in Dresden. We impose the following conditions:

1. The gold preparation must be such as can be manipulated like a silver amalgam, and readily introduced into the cavity.

2. The preparation must, in accordance with all the accepted rules of operative dentistry,—a, adhere perfectly to the walls of the cavity; 6, aisume at once and permanently retain the approximate or perfect gold color which is to be characteristic of it; c, be capable of taking a polish in the cavity; d, and, finally, form in the cavity a firm, compact block of gold, which will not suffer contraction in course of time.

3. The process must be new and capable of being patented.

4. The process becomes the property of the association.

5. With the description of the process, competitors must send in samples of the gold preparation, for which payment will be made at the standard gold value.

6. The name of the sender must not appear either on the description of the process or on the accompanying samples. Both must be marked with a motto, which must also be written on a sealed envelope containing the full name and address of the sender. Competition is unlimited.

7. Processes and samples must be sent in, at the latest, by April 1, 1886.

8. Processes and samples will be tested by the following judges: Herman Bothe, mechanical dentist, Dresden; Dr. E. Geissler, chemist, editor of the Pharmazeut, Central-halle, Dresden; Adolph Werner, dentist, Nice.

9. The decision of the judges will be given, at the latest, by January 1, 1887, from which day the prize will also be payable.

10. Unsuccessful work will be returned, but'the association reserves the privilege of purchasing such work and of entering into negotiations with the senders.

Further information will be cheerfully furnished upon application to Aug. Polscher, editor of the Monaisschrift des Vereins Deutseher Zahnkunstler, Am Markt 3 and 4, Dresden, N., Germany.

Countersunk Tooth-crowns.—Permit me to make a suggestion concerning the excellent new style countersunk tooth-crown. Practically, the only thing to guard against is a failure to make the base-plate fill the countersinks. Care should be taken to pack small pieces of rubber in each countersink until filled, to prevent the flat rubber sheet from so covering the countersinks as to make them valvetight, and shut in air; thus preventing the rubber from entirely filling the cavities around the pins. The same result will follow pouring melted base metal into the flask, unless the hot flask is lightly struck, or jolted, to expel the air shut up in the countersinks. Using such care, the metal or vulcanite will hold these new teeth with a firmer grip than any of the old styles. The teeth themselves are stronger than any others, because the necks are wider from front to back.—W. O. H.

Be-implantation.—In August last I was compelled to extract a lower (2nd) left bicuspid for a gentleman who was anxious to have the tooth saved, but who lived so far distant that it was impossible to have it treated. I advised re-implantation. He finally consented, and I filled and replaced the tooth, after syringing the socket with tepid water and holding the tooth for a few moments in warm water and glycerin. Then, giving him a few capsicum plasters, and instructing him to use them in case of inflammation, I requested him to report in a few weeks. In the latter part of September I received a letter stating that the tooth was only slightly sore for a day or so, and that at the end" of four days he could use it without any difficulty. He reminded me of a remark I had made that if the operation was successful he would not part with the tooth for f>25, and said he wished it distinctly understood that the tooth was not on the market at any price.—G. A. Vawter, Cambridge, III.

By common consent Nitrous Oxide Gas is acknowledged to be the safest anesthetic known, and for minor operations, such as the extraction of teeth, in all respects the best.

Various preparations have been put upon the market with the claim of superiority for them over pure nitrous oxide. We have been solicited to become identified with devices for combining other anesthetics with this gas, but we are opposed, on conviction of their danger, to all such admixtures. We consider that it is of the utmost importance to one administering an anesthetic that he should know exactly what he is using. The various anesthetic agents produce their effects upon the economy by entirely different methods, and the remedies and treatment required, when signs of danger appear, differ accordingly. We are therefore unwilling to deal in any secret or mixed preparations for the induction of anesthesia.

We occasionally receive cylinders for refilling which have a strong odor of chloroform, ether, wintergreen, etc. We cannot know what agents have been employed nor how much that is deleterious may remain in the cylinders, and although it is troublesome and expensive to cleanse them we will not allow them to pass out of our hands until assured of their absolute freedom from all foreign substances. Some manufacturers seek to refill as many of our cylinders as possible, and have even closely copied our labels, evidently with the object of obtaining for an inferior article the benefit of our reputation. The care with which our operations are conducted enables us to guarantee the purity of our product.

Our valves are by far the best in the market, and the reports of loss by leakage have been reduced to a minimum.

Any practitioner desiring to procure our gas and failing to obtain it of his local dealer, can order direct from either of our houses.

We would once more call attention to the statement contained in our circular issued January, 1883, that thereafter, for reasons stated, we would "not fill cylinders of more than 100 gallons' capacity, except those of our own manufacture.'1

PBICES.

In 100-gallon Cylinders, per 100 gallons $4.00

In500-gallon"" 8'60

THE S. S. WHITE DENTAL MANUFACTURING CO.,

Philadelphia, New York, Boston, Chicago, Brooklyn,

Nickel-plated Gasometer and Stand $128.00

"" "complete, with 500-gallon

Cylinder (filled), Tubing, Inhaler, etc 177.50

Japanned Gasometer and Stand 90.00

"" "complete, with 500-gallon Cyl

inder (filled), Tubing, Inhaler, etc. . . . . 139.50

Boxing 5.00

The prices of complete apparatuses vary slightly, as the gas, whether more or less than 500 gallons, is charged at 3J cents per gallon.

(see Opposite Page.)

Designed for those who use large quantities of Nitrous Oxide, or who may desire a highly ornamental piece of office furniture, coupled with a really economical gas apparatus.

The cut represents the nickel-plated Gasometer, mounted on a stand, with a 600-gallon cylinder in position.

The Gasometer will hold 10 gallons of gas—sufficient to completely anesthetize any patient. The usual quantity of gas given to a patient is from 3 to 5 gallons.

If it is desirable to keep the patient under the influence of the anesthetic for a prolonged period (as in a surgical operation), the operator has under his control 500 gallons of gas, by merely turning the key seen in the cut at the right.

On the hell of the Gasometer there is a scale graduated in gallons and fractions of a gallon, so that the operator can readily see how much gas he has administered.

Another valuable feature of this Gasometer is a peculiar water-check or valve, so arranged that though the gas flows freely on the slightest inspiration at the inhaler, it is instantly and automatically shut off by the water when the patient stops breathing. This prevents all waste of gas; it also saves the dentist's time at the most critical moment, as he has only, after having administered the gas, to lay aside the inhaler and proceed at once to operate, without the necessity of shutting any stop-cock. The stand is so constructed that a small (100-gallon) cylinder can be used while the larger cylinder is being refilled.

We also call attention to the fact that there is no liability to loss of gas from leakage, caused by the operator's leaving the valve of the cylinder open, for if there is such escape from the cylinder the bell of the Gasometer will rise, and the operator having his attention called to the waste, will be enabled to correct the difficulty at once.

The gas can be kept for any length of time, and is constantly on hand and always of the best quality.

CHECK ON WASTE OF GAS.

At the suggestion of Dr. ,T. E. Quinn, of Boston, we are enabled to supply a certain detector of leakage of gas from Cylinders,—a small syphon-shaped glass tube, partly tilled with water, for attachment to the connections on the cylinder by means of quarter-inch rubber tubing. The slightest escape of gas will show itself in bubbles passing through the water. By placing the glass tube where it can be seen from the operating chair, the rubber tubing can be led to the cylinder, which may be placed out of sight. We will supply the glass tubes to our customers without charge, upon application at any of our houses.

FUSED NITRATE OP AMMONIA.

Put up in 5, 10, 25, 50, and 100 pound boxes.

Price per pound, including boxing 30 cents.

The complete apparatus is shown in cut, and consists of an iron cylinder containing at least 100 gallons (usually more) of nitrous oxide, liquefied, to which is attached the necessary tubing, with gas-bag and inhaler; the whole inclosed in a stout morocco case lined with velvet.

In manufacturing the Surgeon's Case particular attention has been given to each and every part, sd as to insure not only a complete but the very best apparatus of its kind.

The case is made of well-seasoned wood, is lined with velvet and covered with morocco, and the mountings are nickel-plated. A stout cast-steel ring, neatly japanned, with a heavy set-screw, clamps the cylinder.

The No. 1 Case has a 4J-gallon bag; the No. 2 Case a 7-gallon bag.