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NOTES AND CORRESPONDENCE NOTE ON “CHEMISTS’ PROTECTIVE ASSOCIATION” Editor of the Journal of Industrial and Engineering Chemistry: The recent,proposal [THISJOURNAL, 7 ( I ~ I S ) ,7981 t o form a “Chemists’ Protective Association” seems to call for discussion. I n the first place, as a loyal and interested member of the American Chemical Society, the present writer feels t h a t this Society is intensely practical in t h a t membership in it tends t o increase the efficiency of its members as chemists. Any organization which has this effect is bound t o react favorably upon those responsive t o such influences, and this reaction will ultimately find expression in a fatter pay envelope, if we wish t o look at t h a t aspect of increased efficiency, apart from all other considerations. In the second place, any attempt t o define a “chemist” as a person having “spent four or more years a t an accredited technical school or University in the didactic and laboratory study of all the regular branches of chemistry, and who has received formal statements represented by a degree or degrees t h a t the prescribed courses of study have been satisfactorily completed,” will justly be doomed t o sure and certain failure. There are many men who have had all the advantages of technical training but who are lacking in the essentials of interest, clear-headedness and broad-mindedness. Such men, it is needless t o say, will never be successful chemists. On the other hand, many so-called “quasi chemists” and “laboratory boys, ” in the proper surroundings, may develop into very competent and efficient workers. Men of this type, with a little encouragement, succeed in spite of a lack of technical training. In the third place, the proposed salary scale based on a classification of chemists as “Assistant Chemists” and “Chief Chemists” is artificial, academic, and impractical. Most chemical work in a technical laboratory naturally falls into one of the following classes: ( a ) analytical and control; ( b ) factory development; (c) fundamental research. A given piece of work may overlap the boundaries of two or even all three of the above divisions. It also happens t h a t the aptitude of different men for different classes of work is different so t h a t some men make good research men, but would be dismal failures in developing processes on a commercial scale, or in analytical work. The training a man has had, of course, plays a large part in making him fit or unfit t o do a given class of work, but the native ability of the man himself, his enthusiasm, his “chemical instinct” and “optimistic activity,” or lack of these qualities, must surely be considered in placing men in laboratories and in their subsequent advancement. Looking a t this same subject from another point of view, it so happens that, in different laboratories, the relative importance of the above classes of chemical work may differ. Thus, one company may require but little research work and a great deal of analytical and control work; or a great deal of factory development work may be necessary t o put into practical operation the results of some fundamental research. Now, this question of the class of work required in any one instance, the native ability of a man and his attitude toward his work are all inseparably connected with his advancement. Of these, his ability t o take on added responsibility; to grow and become more efficient; the proper receptive attitude which enables him t o apperceive new ideas and meet new conditions, are of the greatest importance, in determining his salary. If he is capable of doing low-grade routine work, and nothing else, it is but right that he should receive a low salary; for, the lower the grade of work required, the easier i t is t o train a n ordinary boy t o do the work. I n all laboratories that the writer knows
of, there is considerable routine work which is easily mastered by any boy of average intelligence and no trained man should be foolish enough to waste his time doing such work; if such a chemist should be found he could rest assured t h a t the business man would pay him no more than he would pay the laboratory boy, because he would be worth no more. On the other hand, some of the so-called “laboratory boys” or “quasi chemists” happen t o be above the ordinary in intelligence and men of this sort will rise and justly so. It seems to the present writer t h a t these questions of the definition of “chemist , I ’ the classification of chemists, and the salaries they are to receive, should be, and are generally in actual experience, answered on the basis of the efficiency of the individual worker: $IZOO.OO per year is too much t o pay to a n inefficient chemist who lacks interest and enthusiasm in his work and whose growth is a t a standstill; $jooo.oo per year is too low a limit to place for a n active, energetic and growing head of a laboratory. I n fact, why place any limits in either direction? I n conclusion, the writer feels that any proposal to form a “Chemists’ Protective Association” should be most emphatically opposed by all chemical workers and chemically trained men who have the real interests of the chemical profession a t heart. CLEVELAND, OHIO WILLIAMC. MOORE
ON GERMICIDAL EFFICIENCY OF DENTAL CEMENTS
Editor of the Journal of Industrial and Engineering Chemistry: A letter written by W. 1‘-B. Ames, representing the W. V-B. Ames Company, referring t o my paper on “The Germicidal Efficiency of Dental Cements” (THISJOURXAL, 7,195), appeared JOURNAL, 7, 723. in THIS I n the first paragraph Ames misquotes from my article as shown by comparing the following excerpts: F r o m “ T h e Germicidal Efficiency of Dental Cements‘’ b y P a u l Poetschke, THIS JOURNAL,M a r c h , 1915.
F r o m Ames’ 1 e t t e e T m s
JOUR-
NAL,a u g u s t , 1915: I n THIS JOURNAL,March, 1915, appeared
an
article
by
Paul
Poetschke, entitled “ T h e Germicidal Efficiency
of
Dental
Cements.”
T h e concluding paragraph promised reports on the comparative strength and
other
properties.
These
re-
ports would be, a s Mr. Poetschke states, “of more immediate interest t o t h e dental profession,”
and i t
will be b y clinical experience in t h e hands of the dentist t h a t t h e subject will receive its final analysis and probably he reported mainly in t h e dental literature.
FROM IKTRODUCTION: “It is possible t o measure the
germicidal efficiency of material of this character in precisely t h e same way a s i t is possible t o measure the germicidal efficiency of disinfectants. It is therefore obvious, especially in view of t h e varied composition of these cements, t h a t a thorough investigation of this subiect is of immedyate interest t o t h e dental profession, a s well a s t o chemists a n d bacteriologists who m a y he called upon t o report on t h e ermicidal power of dental cements. he object of this paper is t o show the comparative germicidal power of these cements, a n d also some of t h e compounds used in their production.”
5
FROM CONCLUSIONS: “ T h e germicidal efficiency of a dental cement is merely one of t h e properties which are of importance. M a n y other physical properties such as resistance t o saliva, hardness crushing strength, constancy of ;olurne, etc., are also of importance. T h e relation of t h e germicidal efficiency t o these other properties is being investigated in this laboratory, a n d t h e results will be published in future papers.”
The exact quotations from Ames’ letter and my article are given because of the evident intention of Ames to minimize the importance of this investigation to the dental profession. As far as the clinical significance of these bacteriological tests is concerned, one can hardly fail to appreciate that a copper
Nov., 1915
T H E J O U R N A L OF I N D C S T R I A L A N D E N G I N E E R I N G CH E M I S TR Y
cement is used primarily on account of its germicidal properties. Therefore, such tests must be relied upon to secure firsthand cvidence in this direction. In surgical practice the carbolic coefficient of a disinfectant is accepted as a reliable criterion of its efficiency, and likewise the germicidal efficiency of a copper cement can be accepted as a reliable indication of its clinical efficiency. I n connection with this letter Xmes reproduces an illustration which he says is “ t h e one illustration criticized by Mr. Poetschke, the criticism being mostly that only comparative inhibition has been shown and that there had been no bacterial count.” Here again, Ames attempts to minimize the criticism which I made of his paper. This illustration was the only one which appeared in Ames’ paper, and therefore the only one which was open for consideration. However, reference t o my article will show t h a t every statement made by Ames, bearing directly on the subject of germicidal properties, was fully quoted and criticized in my papel A copper cement exerts its germicidal effect in two distinct stages, that is, both in “plastic” and “ s e t ” condition. It thus exerts an initial sterilizing influence when inserted and a permanent germicidal influence after it is set. The initial sterilizing influence is not of much importance because the local application of a liquid disinfectant would accomplish the same purpose. The permanent germicidal action of the cement in the set condition is the main desideratum. Ames apparently fails to appreciate these facts in referring to “ a cavity from which all infected material had not been removed, there being, for this reason, a need of a sterilizing filling.” Ames further states in his letter: “ I t is well known by the dental profession t h a t a real copper oxid cement mill furnish the means of sterilizing of such an infected area, and yet furnish a mass, after proper setting, which is so highly insoluble that it w-ould show potency only in the hardened state equal to the best of the so-called copper cements tested by XIr. Poetschke, including t h a t made by the I,. D. Caulk Co., the employers of RIr. Poetschke.” I n this statement Ames intends t o create the impression t h a t the dental profession accepts and knows these statements to be facts, when as a matter of fact, the dental profession does not know or accept these statements, Nowhere in the dental literature does any authoritative statement or proof appear which substantiates this assertion. Arnes insinuates t h a t the black copper cement of his manufacture, which is referred to in the illustration, is not more highly germicidal in the hardened state, because of its “highlr insoluble ” character. M y experimental data, which I shall shortly publish, shows that this black copper cement, made by Ames and referred to as so “highly insoluble,” suffers the greatest relative loss in strength in saliva of twelve copper cements which are on the market to-day with but one exception, and that is also a black copper cement. Ames has attempted t o claim the authority of the dental profession for a statement which has absolutely no basis in fact. The ambiguous statements made by Ames regarding the “ cement-making property of the cuprous and cupric oxids” have absolutely no relation to the subject under discussion, because a copper cement need not contain cuprous or cupric oxides in order t o possess the requisite germicidal power, strength, resistance to saliva, or any of the properties demanded of a copper cement. It is immaterial whether a copper cement contains cuprous or cupric oxide, but it must contain some compound of copper which in itself has sufficient germicidal power to secure the required germicidal efficiency in the finished cement. Of course, it is understood that any copper cement must have, in addition to germicidal power, secured by the addition of a potent compound of copper, all of the other physical and chemical properties demanded of a product of this character. My investigations, which will be published shortly, show t h a t cuprous
IO01
and cupric oxides need not be depended upon for any cementmaking property which they may possess, and their elimination from copper cements, as Ames infers, is greatly desired by the dental profession, because of the limitation imposed on copper cements containing cuprous and cupric oxides on account of their color. Ames refers to a “difference in germicidal efficiency between a real copper oxid cement and an oxyphosphate of zinc cement, more or less modified by a copper compound, each in the freshly mixed state” as being “so great t h a t results may be shown which appeal to the naked eye instead of needing microscopical count.” I have referred a t length, in my paper, to the fallacy of testing a dental cement for its germicidal efficiency in the “freshly mixed state,” and I wish to emphasize the statement contained in my original article, namely, t h a t the tests employed by Ames failed t o give any information concerning the germicidal efficiency of a dental cement. I fail to understand Ames’ reference to “ microscopical count” except to assume t h a t Ames does not know that the colonies of bacteria are not counted by the aid of the microscope, but by the naked eye. In the last paragraph of his letter Ames describes his illustration in part by stating, “ N o . 2 , a zinc oxid cement carrying a small percentage of oxid of mercury (yellow),” whereas his original paper read, “ N o . 2 , oxyphosphate of zinc containing a small percentage of mercurous iodid.” This certainly cannot be a typographical error and it is needless for me to call attention to the radically different character of these two compounds of mercury. This does not inspire confidence in the illustration. Ames states that this illustration shows “inhibition of bacterial growth ” and that the “inoculation was overwhelming,” yet reference to the illustration fails to show a single colony of bacteria, notwithstanding the fact t h a t it is supposed to depict a n inoculated Petri dish. The illustration is plainly not a photograph and naturally cannot be accepted as showing “inhibition of bacterial growth.” Even if i t did show what is intended. the test is of no value as regard establishing germicidal efficiency of the material. In conclusion, I wish to point out that Ames does not present a single criticism of my article but merely repeats and adds t o the statements contained in his article which I fully criticized as being of pseudo-scientific character. In this letter additional erroneous statements and conclusions are presented by Ames which have no basis in fact and are unsupported by any evidence whatever. The illustration presented is not worthy of consideration, because it does not show “inhibition of bacterial growth,” and further, the description does not agree with Xmes’ original article. PAULPOETSCHKE, DEPARTMENT OF CHEMISTRY, THE I,. D. CAULKCo. MILFORD, DELAWARE. AUGUST 26, 1915
THE “PURE FOOD LAW” E d i t o r of the Journal of Industrial and Engineering Chemistry: For the past nine years i t has been of profound interest to follow the prosecutions under the “Pure Food Laws.” Being of an analytical mind I carefully went into the fundamental conceptions of the lam, its rigid legal and logical interpretation, its effect upon commerce, international and interstate, and finally I examined the details of the administration of this, and attempted to ascertain, as nearly as possible, whether justice or injustice had been inflicted on those who had come into contact with the law as defendants in criminal prosecutions brought by the government. lLIy conclusions, after t h e nine years of investigation, are t h a t in many cases the defendants pleaded guilty to the charges brought against them, although they were neither legally nor morally guilty, merely to escape the annoyance of a trial, always distasteful to busy and enterprising men of affairs.
