PRESIDENTIAL ADDRESS SECTION F. 107 



course ; think alone of the number of cases of delirium tremens 

 which never reach a mental hospital, because they have died 

 beforehand for want of proper treatment; or of the many cases, 

 with less violent symptoms, who manage to struggle through 

 their attacks somehow, but who during this time cause much 

 anxiety and excitement to their surroundings. 



Amongst the troops that could not get excessive quantities 

 of drink during the great war, the incidence decreased consider- 

 ably ; and the same appears to have happened in America since 

 prohibition. 



There are a few other poisons and drugs the excessive use 

 of which at times causes mental derangement; for example, 

 veronal, morphia and cocaine. The incidence of these psychoses 

 is, however, not great, although there are indications that it rises 

 in places where alcohol is prohibited. In the native mental 

 hospitals of this country we see a certain number of psychoses 

 where Cannabis indica, or dagga, is the only or the most import- 

 ant etiological factor. Here again, we shall be able to prevent 

 the mental diseases so caused, if we succeed in the prevention of 

 the use of these drugs. 



I have already mentioned that in the course of certain acute 

 infections mental disorders may occur. Amongst infections of a 

 more chronic character, none is more important and disastrous in 

 its relation to psychiatry (and neurology) than syphilis. The 

 study of this affliction received a fresh impetus in 1905 through 

 the discovery by Schaudinn and Hoffmann of the mici^o-organism 

 which is responsible for it, Spirochoeta pallida. A few years 

 later, Ehrlich and Hata succeeded in manufacturing salvarsan 

 (and subsequent derivatives) and new avenues were opened up for 

 more extensive and effective treatment. In the latter part of 

 last century alienists had already realised the probability that a 

 previous syphilis infection was often responsible for the develop- 

 ment of certain nervous or mental diseases. Thanks to more 

 accurate clinical and laboratory methods, this probability has 

 become a scientific fact, and we now know for certain that a great 

 number of patients of psychopathic clinics are there solely on 

 account of a previous infection. The figures for the Union for 

 1919 and 1920 are surprisingly low, for example, 6 per cent. ; a 

 few years ago they were distinctly higher. Further, syphilis, 

 like alcohol, may be a contributing factor to almost any form of 

 insanity. The percentage of admissions where lues is the 



principal factor, varies greatly in different places and years, 

 namely, 4 to 36 per cent. The most frequent and important 

 psychosis of this kind is the so-called progressive or general 

 paresis, an affliction which usually attacks people in the prime 

 of life, and which, with a great variety of signs and symptoms, 

 almost invariably leads to a progressive mental and physical 

 disintegration, and finally death. For it must, alas ! be admitted 

 that while our methods of treating the first, second and third 

 stages of lues have improved considerably of late, we are still 

 well-nigh powerless with regard to general paresis. It is true, 

 that by means of the modem treatment we succeed more fre- 



