436 



NATURE 



[January 31, 191 



value to the surgeon and radiologist in their combined 

 efforts. 



Unless there is a suspicion of septic poisoning a 

 bullet is generally best left alone, but shell fragments 

 are usually dirty, and the nature of the damage they 

 ini?ict along their course makes it important that their 

 exact position should be known. It is in such cases 

 that X-ray stereoscopy attains its fullest delicacy. For 

 example, the location of small foreign bodies near the 

 eye, or actually in the eyeball, can be carried out to 

 the hundredth of an inch. 



In the case of a fracture the stereoscopic radio- 

 graph reveals the direction of the fracture and the dis- 

 position of the broken bone, and so assists the surgeon 

 in deciding on the method of reparation. After the 

 bone has been set, the progress of the recovery can 

 be • clearly followed in the subsequent photographs — 

 whether the parts are joining up, whether new mate- 

 rial is forming. The sequence of radiographs is in- 

 cluded in the record of each case. X^e total .number 

 of photographs already taken at the various hospitals 

 since the war commenced amount to many hundreds 

 of thousands. Very valuable data will be obtained 

 when time allows the radiologist to go carefully over 

 all the accumuated records of cases. . 



The value of the X-rays in diagnosing chest com- 

 plaints has been established again and again in this 

 war. This is the case particularly with incipient 

 tuberculosis, where early diagnosis is of great import- 

 ance. Not only the diagnosis, but the treatment of 

 tubercular glands has been attended with considerable 

 success. Great attention has been paid in this war 

 to the soldier's teeth, and very rightly. Here, again, 

 the X-rays are playing their part and dental radiology 

 has become an important subject. No more than men- 

 tion can be made of the splendid work of "opacity" 

 radiology, which can diagnose with routine certainty 

 diseases of all parts of the alimentary canal. This 

 has been of great service in examining Army recruits 

 of doubtful medical fitness. 



A word should be said as to the invaluable results 

 obtained from single-flash exposures, especially in heart 

 and lung conditions. Another war development of 

 radiology is its employment by the orthopaedic surgeon 

 in his efforts to restore damaged limbs. 



But the beneficent effects of the X-rays do not end 

 W^ith radiography. They have achieved wonderful re- 

 sults, not only in the diagnosis, but also in the repair 

 of wounds. Amongst the minor tragedies of the war, 

 few are more pathetic than the ghastly mutilations and 

 disfigurements caused bv shell wounds of the face and 

 head. Many of our soldiers would seem to be doomed 

 to a life of perpetual misery and humiliation, but by 

 the wonderful plastic operations of the surgeon they 

 can be restored to at least a semblance of their former 

 selves. The radiologist's part in such work is to 

 render scar-tissues pliant, to depilate hair from the 

 scalp and skin surfaces concerned, to render the trans- 

 ferred flaps of skin pliant and more adaptable to their 

 new positions, and to stimulate generally the healing 

 process in both flaps and bone. For these purposes 

 he employs radiation treatment, either X-rays or' radium 

 rays. 



In the treatment of septic wounds and persistent 

 sinuses, the most extraordinary success has resulted 

 from a combination of X-rays and ultra-violet rays. 

 Hyperthyroidism, or " soldier's heart," has been suc- 

 cessfully treated by X-rays and radium rays. 



The electro-therapeutist has also been prominent in 

 war work. Countless electrical departments have 

 been established in military hospitals throughout the 

 country for the treatment of war injuries. Quite one- 

 half, if not more, are gunshot wounds of the nerves 

 with paralysis of the muscles. These cases are sent 

 for electrical examination of the injured nerves and 

 NO. 2518, VOL. 100] 



I subsequent electrical treatment. Many cases of war 

 I wounds, more particularly those of the uncomplicalt (1 

 but inert type which refuse to heal, are treated elec- 

 trically. Simple application of a direct current stimu- 

 lates the process of repair, and sluggish wounds at 

 once commence to heal. "Trench feet," which 

 occurred in large numbers last winter, receive benefit 

 by electrical treatment. Cases of shell-shock and 

 neurasthenia and other functional disorders of the 

 nervous system, some of which are seldom or never 

 seen in times of peace, are now being cured in large 

 numbers by electrical means. 



And so the story goes on. The radiologist and the 

 radio-therapeutist have found their reward in the grati- 

 tude of many men to whom they have once more 

 made life endurable. 



The outbreak of war found the X-ray manufac- 

 turers, like everybody else, quite unprepared. The 

 greatest credit is due to them for the splendid way 

 they threw^ themselves into the breach and turned out, 

 in record time, unprecedented numbers of outfits for 

 the Army. The X-ra)' bulb manufacturer was at once 

 confronted with the absence of the glass, which Ger- 

 many had hitherto supplied. The English glass manu- 

 facturer had to face the task of producing a uniformly 

 good glass which would stand up, without puncturing, 

 to the high voltages \^hich obtain in practice. The 

 problem was very difficult, but it is gradually being 

 surmounted by State aid. In the meantime our Amer- 

 ican and French friends came to the rescue. 



It is remarkable how slight have been the changes 

 in design experienced by the target tube. He would 

 be a bold man, nevertheless, who would assert that 

 the present design has approached finality. All X-ray 

 tubes are, in fact, extraordinarily inefificient things. 

 Under favourable conditions they make use of rather 

 less than one part in one thousand of the energy 

 imparted to the cathode rays. 



The Coolidge tube, first introduced nearly four years 

 ago, has been considerably improved in detail, and 

 now claims pride of place among X-ray tubes. It is 

 not entirely free from defect, and its rays are no more 

 homogeneous than those from an ordinary bulb, but 

 its elasticity, precision, ease of control, long life, and 

 relative freedom from inverse current make it an in- 

 valuable addition to the radiologist's equipment. Some 

 wonderful output figures have been obtained by 

 Coolidge on experimental water-cooled models. One 

 tube was run continuously for many hours at 200 

 milliamperes and 70,000 volts, the power input being 

 14 kilowatts, i.e. about 19 h.p. It is anticipated that 

 this figure will be shortly increased to 50 kilowatts. 



It was hoped on its introduction that the Coolidge 

 tube would be the means whereb}' X-rays approximat- 

 ing to the hardest 7 rays from radium would be 

 obtainable. Such anticipations have not been realised. 

 In some recently published work Sir E. Rutherford 

 describes measurements on the very hardest rays 

 emitted by a Coolidge tube excited by close on 200,000 

 volts. In order to filter out the hardest rays present 

 he passed them through i cm. of lead, the reduction in 

 intensity being more than a millionfold. The residual 

 ravs proved to have a wave-length of about o-o6 A.U., 

 which may be compared with Rutherford's latest esti- 

 mate of the wave-length of the hardest 7 rays from 

 radium C — between 002 and 0-007 A.U. In other 

 words, the Ra 7 rays in question corresponded with 

 X-rays generated by voltages between 600,000 and 

 2,000,000— figures to which no X-ray tube of present- 

 day design could possibly stand up, even if we had the 

 means to produce such voltages on a practical scale. 



As to the composition of the X-ravs generated by an 

 X-ray bulb, we know now that the rays consist in 

 general of two groups :■ — 



(a) A continuous spectrum of rays with a sharply 



