600 American Nervousness. [September, 
skill and great number of our oculists are constant proof and 
suggestions of the nervousness of our age. 
It is demonstrable that nervous diseases have increased in 
recent periods ; and that, with this increase of nervous 
symptoms, there has been also an increase in the aesthenic 
forms of disease, and a decrease in the sthenic forms ; and, 
correspondingly, that there has been a change in the methods 
of treatment of diseases ; that neurasthenia — nervous sus- 
ceptibility — has affeCted all or nearly all diseases, so that 
nearly all illnesses occurring among the better class of 
people — the brain-workers — require a different kind of treat- 
ment from that which our fathers employed for the same 
diseases. 
The four ways by which we determine these faCts are — 
first , by studying the literature of medicine of the past 
centuries ; secondly , by conversation with very old and expe- 
rienced practitioners — men between the ages of seventy and 
ninety — who link the past with the present generation, and 
remember their own personal experience and the practice of 
medicine as it was fifty years ago ; thirdly , from our own in- 
dividual experience and observation ; fourthly , by studying 
the habits and diseases of savages and barbarians of all 
climes and ages, and of the lower orders about us. 
Statistics on this subject are of very little value, for 
reasons that will be clear to those who are used to statistics, 
and who know how they can be handled. Longevity has 
increased almost pari passu with this increase of nervous- 
ness and change in type of disease, and this has been a 
stone of stumbling and rock of offence to those who have 
discussed this subjeCL Both faCts are true; longevity has 
increased among the brain-working classes, and nervousness 
has also increased. These two apparently opposite faCts 
are harmonised by a third faCtor which those who have 
studied this subject have failed to reach — namely, nervous- 
ness is not only consistent with longevity, but actually 
favours it, by preserving the system from attacks of acute 
inflammatory disease. We do not bear blood-letting now as 
our fathers did, for the same reasons that we do not bear 
alcohol, tobacco, coffee, opium, and physical pain as they 
could. The change in the treatment of disease is a neces- 
sary result of the change in the modern constitution. The 
old-fashioned constitution yet survives in numbers of people, 
and in such cases the old treatment is oftentimes better than 
the modern treatment. 
In the study of this subject I have compared a very large 
number of books of travel, and I have arrived at this faCt, 
