February 22, 1889.] 



SCIENCE. 



137 



tise. An irregular practitioner attempted to evade this legal re- 

 quirement, and was prosecuted. The case, being decided adverse 

 to him, was finally carried to the Supreme Court of the United 

 States on the ground that the act was invalid. This court sus- 

 tained the lower courts in the following opinion : " The power of 

 the State to provide for the general welfare of its people authorizes 

 it to prescribe all such regulations as may be necessary to secure 

 the people against the consequences of ignorance and incapacity as 

 well as deception and fraud. One means to secure this end is the 

 method adopted by the State of West Virginia. If the means 

 adopted are appropriate to the calling or profession, and obtainable 

 by reasonable study and application, no objection to their validity 

 can be raised." 



Contagiousness of Consumption. — Mr. MacMuUen, in 

 the Australasian Medical Gazette, calls attention to the danger to 

 which healthy travellers are subjected by consumptives. To illus- 

 trate this danger, he narrates a case in which a healthy man, on the 

 voyage from London to Australia, was placed in the same state- 

 room with a consumptive in search of health. Now that consump- 

 tion is regarded as a communicable disease, there is no longer 

 excuse for this commingling of well and sick in such confined quar- 

 ters as a ship's stateroom. Steps should be taken by the owners 

 of steamships and other vessels to separate those who are so un- 

 fortunate as to have consumption, from those that are healthy, to 

 the degree, at least, that the unsuspecting traveller would not be 

 required to breathe the air impoverished and possibly infected by an 

 invalid suffering from pulmonary consumption. 



Doctors Advertising. — The Board of Health of Illinois a 

 few months ago revoked the license of H. G. Wildman, a physician, 

 the chief charge being that he had overstepped the ethics of the 

 profession by advertising his success and skill in newspapers. Dr. 

 Wildman then appealed the case to Gov. Oglesby, and he rendered 

 his opinion a few days since, reversing the decision of the Board of 

 Health, and claiming that a physician should not be debarred from 

 practice because he advertises what he can do and has done. Dr. 

 Wildman expends over forty thousand dollars yearly in advertising 

 in papers all over the Union, and several of the Illinois papers went 

 on his bond in the action. 



Public Medical Libraries. — In the proceedings at the re- 

 ception given to Dr. Oliver Wendell Holmes, says the New York 

 Medical Record, on the occasion of his presenting his library to the 

 Boston Medical Library Association, Dr. R. M. Hodges, president 

 of the association, gave some facts regarding the public medical 

 libraries of this country. " First," he said, " in point of time, is 

 the library of the Pennsylvania Hospital, founded in 1760; second, 

 that of the College of Physicians in Philadelphia, founded in 1788; 

 third, the New York Hospital Library, in 1796, etc. Of course, the 

 library of the surgeon-general's office has surpassed in size all these, 

 having a large annual appropriation and a magnificent librarian. 

 Next in rank comes the library of the College of Physicians ; next, 

 that of the Academy of Physicians ; and our library comes fourth 

 in rank. After that come the Medical Department of the Public 

 Library of Boston, and the New York Hospital Library. In other 

 words, although the youngest of these seven libraries, ours has 

 already passed three of them. We have nearly twenty thousand 

 volumes.'' 



Danger in the Postage-Stamp. — The Sanitary News calls 

 attention to the fact that a postage-stamp may in various ways 

 convey contagion. One of the simplest and most plausible is that 

 in which a postage-stamp, partially attached to a letter to pay re- 

 turn postage, is sent by a person infected with some disease to an- 

 other person. The disease is transferred, in the first place, to the 

 adhesive stamp through the saliva, and in being attached to the 

 letter by the receiver the poison may be transmitted to him in turn 

 through the saliva. Another cause may be the infection of the 

 stamp with disease germs. The stamp, having been exposed in a 

 room where a diseased person lies, may become slightly moistened, 

 and thus retain the germ. 'That this is true can be proved very 

 simply by a microscopical examination. We often see a person 

 holding change for a moment in the mouth, probably not knowing 

 that investigation has shown that disease germs can be carried by 



money. If one could see through what hands the money has 

 passed, he would hesitate before using such a third hand. Silver 

 money is as bad as paper money ; but, while many would hesitate 

 to hold a dirty bank-note in their mouth, they think that a silver 

 piece, because bright, is apparently clean. 



Sanitary Plumbing. — In speaking of the effects of sanitary 

 plumbing, the Sanitary News says, " Dr. A. R. Carter, of the 

 health department of Baltimore, has published some interesting 

 statistics in regard to the effects of sanitary plumbing. He says 

 that during a period of fifty-four years, from 1830 to 1883 inclusive, 

 there were in that city 12,197 deaths from scarlet-fever, being an 

 average of 226. In the last of those years there were 334 deaths. 

 But the city council then passed an ordinance regulating plumbing, 

 and in the years since, there has been a remarkable decrease in the 

 mortality from scarlet-fever. In 1884 there were 104 deaths; in 



1885, 67 ; in 1886, 32 ; and in 1887, 36 ; making a yearly average 

 of 60, but with a plain tendency to decrease. The yearly average 

 of deaths from diphtheria has in the same way diminished from 

 469 to 234." This kind of reasoning is, in our judgment, very 

 fallacious. If the diminution of diphtheria in Baltimore is to be 

 attributed solely to the improvement in plumbing, why did not the 

 same result take place in New York and Brooklyn, where the im- 

 provement in plumbing has been most marked since 1882 } In that 

 year in New York there were 1,009 deaths from diphtheria ; in 1884, 

 i,ogo; 1885, 1,325 ; 1886, 1,727; 1887, 2,167. In Brooklyn in 1883, 

 409 deaths occurred from this disease; in 1884, 385; 1885, 519; 



1886, 782; and in 1888, 984. So far as scarlet-fever is concerned, 

 the statistics of Brooklyn show no such marked difference in the 

 various years as could be attributed to the plumbing. Thus in 

 1883 there were 505 deaths from this disease ; in 1884, 218 ; 1885, 

 363; 1886, 340; and in 1888, 475. In New York there was a 

 notable decline from 2,066 deaths in 1882, to 744 in 1883, which 

 could not be attributed to improvements in plumbing. Since that 

 time the number of deaths has not been as high, but the diminu- 

 tion cannot, we think, be traced to the better plumbing. We do 

 not wish to be understood as disbelieving in the value to life and 

 health of good plumbing, — on the contrary, we regard it as one of 

 the most important factors in the preservation of health, — but we 

 do not think it the only factor, and believe it to be a mistake to at- 

 tribute the reduction of contagious disease in any small series of 

 years to a single cause. 



ELECTRICAL NEWS. 

 Hertz's Researches on Electric Oscillations. ^ 



After proving the existence of displacement currents in dielec- 

 trics, Hertz turned his attention to the propagation of waves in 

 wires. To investigate this phenomenon, he used the apparatus 

 shown in Fig. 9 (Fig. 1 1 in article). Here the primary circuit con- 

 sisted of the two brass plates AA', connected by a conducting wire 

 in which was an air-space. The secondary used was either B or C, 

 a rectangle and circle of wire respectively, the periods of which 

 were equal to that of the primary circuit, — about .000000014 of 3. 

 second. The conducting plate P was placed behind and close to 

 A, and a wire was taken from it in the direction shown, passed 

 through a window, and at a distance of 60 metres was buried in 

 the ground. Now, when the induction-coil is working, and oscil- 

 lations occur in the primary circuit, disturbances are caused in the 

 circuit Pmn, because of the induction of A upon P; and the 

 period of this disturbance is of course equal to that of the primary. 

 If the wire mn were short, there would be danger of disturbances 

 from reflected waves, but 60 metres was found to be a sufficient 

 length to obviate this. 



When electrical waves pass through the wire, we should find 

 loops and nodes, as in any other form of oscillation. To test this, 

 secondary circuits whose periods were approximately that of the 

 primary were brought close to the wire, and were moved along it, 

 the result being noticed at different distances. As the secondary 

 passed along, points of maximum and minimum effect were ob- 

 served at regular intervals. The results are interesting. In the 

 first place, the distances of minimum effect were — 0.2 metres, 



1 Continued from No. 314. 



