Concerning the Employment of Light in the 
Treatment of Disease. 
A PAPER READ BEFORE THE NASHVILLE ACADEMY 
OF MEDICINE, AUGUST 4, 1892. 
By Will F. Arnold, M. D., 
Passed Assistant Surgeon oj the United States Navy. 
NASHVILLE, TENN.: 
Brandon Printing Company. 
1892. [Reprint from the Southern Practitioner, September, 1892]. 
CONCERNING THE EMPLOYMENT OF LIGHT IN THE 
TREATMENT OF DISEASE.* 
BY WILL F. ARNOLD, M.D., 
Passed Assistant Surgeon, United States Navy. 
Mr. President and Gentlemen of the Academy: I believe that there 
is nowhere a well-known published account of the employment of 
a burning-glass (or of a reading-glass) for a therapeutical purpose; 
and this, upon reflection, will appear none the less strange when 
we consider the whilom popularity of counter irritation, and ob- 
serve that the efficiency of concentrated sunlight as an agent for 
immediate vesication, entitles it to rank with stronger water of 
ammonia and with Corrigan's button-cautery, otherwise called 
the thermal hammer. 
In December, 1890, I observed a physician in San Francisco, 
California, concentrate a beam of sunlight upon a small papil- 
loma just inside the meatus urinarius of a patient recovering from 
gonorrhoea, using for that purpose a double convex lens. My 
inquiries elicited the fact that he had learned its use from 
a practitioner in that city, a Dr. Fryer, who had purchased it 
as the secret remedy of a cancer doctor, and who had employed 
it, presumably according to directions secured in the trade, in 
cases of carcinomatous breast, of epithelioma, and of lupus. I 
am not informed that positive diagnosis was reached in any of 
these cases by other means than gross clinical appearances, but a 
paper was read by Dr. Fryer on the subject of this treatment of 
maglignant disease before a local medical society, and one or 
more of his former patients were exhibited, illustrating cures. 
With this impetus I have collected the following observations 
bearing upon the subject, whose interest lies in their novelty and 
*A paper read before the Nashville Academy of Medicine, Aug. 4,1892. 2 
iii their possible value as predictions, pending careful and reliable 
experimentation: 
A Russian observer has announced his discovery of anaesthetic 
effects in the electric light beam; and workmen at Creusot, 
France, where much electrical welding is done, have exhibited 
pathological conditions assigned to its intense and prolonged ac- 
tion. Its ability to penetrate into living tissues is shown by the 
possibility of laryngoscopy with the light applied to the neck 
over the larynx and by the common light-test for pus or for a neo- 
plasm in an antrum. 
Recently Tesla, the inventor of the first alternating-current 
dynamo, has produced an electrical current of from one million 
to two millions of vibrations per second, which has enabled him to 
dispense with Geisler's vacuum tubes in the production of light. 
This light, which appears to be unassociated with heat, and whose 
waves may be made nearly a foot long, passes between somewhat 
distant poles with the effects of the aurora; and vacuum bulbs 
placed between more widely separated terminals will glow bril- 
liantly. Actual contact with glass or other substances, as in 
Crookes' and Geisler's experiments, is unnecessary. It is hoped 
that the resistance of fog to this light may be overcome ultimate- 
ly. This approach of the rate of electrical vibration to the rate of 
light vibration has deprived electricity of its lethal effects upon 
the human body, however great its intensity or high its potential. 
Tesla, in his lectures in England and on the Continent, made 
contact with a terminal capable of giving a spark several inches 
long with an iron bar held in one hand and used his other hand 
as one of the plates for a light. A vacuum tube also held in this 
hand was made to glow very brilliantly by the current, which 
passed through his body and entirely failed to affect it. M. de 
Arsouval (La Semaine Medicale) reports the statement that one- 
five-hundredth part of the force of the current actually employed 
would have been instantly fatal. 
The absence of heat from the light thus produced recalls the 
discontinuous phosphorescence of some earths under high tension 
currents in high vacua and the voluntary brilliant intervals of 
the luminous segments of the abdomens of glow-worms and fire- 
flies, which last are accompanied with no sensible, or at least 
measurable, liberations of heat. 3 
I shall not consider further the effects and properties of arti- 
ficial light; and by the unqualified word light I shall refer to 
that which emanates from the ultimate parent of life on'the earth, 
"the symbol and vice-regent of the Deity." 
The salutary effects of direct sunlight in moderate amount on 
animal life generally, are axiomatic, and in some other countries 
the sun exposure of a building or of a room influences greatly 
its commercial value. This idea has its foundation on the belief 
that the sun can and does destroy the germs of diseases that do, 
like sins, so easily beset us. In the most populous parts of Asia, 
open sewers, or rather no sewers at all, are used for the avowed 
purpose of securing the disinfection of the sewage by sunlight; 
and, while less remote objections to the system than Kipling's (in 
his poem "Municipal") will suggest themselves, some value must 
attach to the practical adoption of the idea. 
Sun baths, tinctured or otherwise, have shared in general the 
fate of tar-water, and for the same reason-the excessive zeal of 
their promoters. It cannot be determined at present how much 
or how little of the climatic benefits to pulmonary phthisis are 
ascribable to the sunlight, but its part in the open-air life, so 
strongly urged to all such sufferers, cannot be insignificant. 
In Peru, there is an establishment where syphilis is treated by 
the enforcement of a very meagre diet and profuse diaphoresis, 
induced by covering the patient with hot sand, until great reduc- 
tion in weight results: then prolonged exposure to the sun's di- 
rect rays is practiced with as little protection to the patient as is 
consistent with humanity. My informant, a naval officer of my 
own corps, much inclined to investigation of such matters, was 
disposed warmly to commend the results secured. He was satis- 
fied that no alterative medicine was used. 
Downes, Blunt, and Tyndall did not employ solely pathoge- 
nic organisms; and later experiments have shown that it is gen- 
erally true of these organisms that exposure freely to the light 
prevents their exuberant growth and the elaboration of their 
special deleterious product. 
Excluding the influence of the attendant heat, which may 
hinder bacteriological growth by dessication and destroy mildly 
resistant germs as heat, the disinfectant action of direct sunlight 
is well attested. 4 
Ducleaux (JJhimie. Biologique Encyclop. Clinique, Paris, 1883.), 
with his great forcibleness has striven to draw attention to the 
prophylactic influences that light and air exert by disinfecting 
effluvia. 
German Sims Woodhead ("Bacteria and Their Products," p. 
277.) makes this statement concerning anthrax spores, the stand- 
by for extreme resistance of bacteriologists: 
"The only other physical condition that appears to be fatal, or 
at any rate injurious, to anthrax spores is strong sunlight; this 
appears to deprive them in whole or in part of their power 
of further development in a most remarkable manner, always 
causing distinct attenuation of their pathogenic virulence before 
completely destroying them." 
Janowski (Centralbl. f. Balct. und Parasitenk. Bd. VI, Nos. 6-9, 
1890.) found that the diffused light of a cold winter's day dis- 
tinctly hindered the growth of the typhoid bacillus in pure a cul- 
tivation in gelatine. He further proved that direct sunlight 
killed this organism in fluid cultures in from four to seven hours, 
diffused daylight requiring a much longer period to suspend their 
development and propagation This was entirely independent of 
any oxidation of their food material by the action of the chemi- 
cal rays of light, which appeared to affect their protoplasm di- 
rectly and to render them incapable of existence. By employ- 
ing various diathermanous and athermanous substances, he reached 
the conclusion that both sunlight and daylight held their hurtful 
influences upon this bacillus in their chemical rays, which agrees 
with the results obtained by Englemann, who, observing some 
motile chromogenic bacteria in fluid illuminated by the rays from 
a micro-spectral objective, found that they always moved to the 
red end of the spectrum to avoid, as it would appear, the chemi- 
cal rays at the violet end. 
The foregoing suggests a factor in the purification of the water 
of running streams not much emphasized at present. Though 
not to be relied on to purify drinking water, light's disinfectant ac- 
tion, from the exposed situation of most streams, must equal that 
of oxidation, of which so much has been said. The penetration 
of light into sea water in the smoothest weather is given as 1580 
feet. 
Koch observed just prior to the promulgation of tuberculin 5 
that tubercle bacilli would not grow on culture media in direct 
sunlight, and that it or even ordinary daylight was fatal to them 
in from a few minutes to several days. 
Even diffused daylight has a pronounced action in killing the 
Klebs Lbffler bacillus, while, in the presence of air, its ptomaine 
or toxalbumin is rapidly modified by sunlight. 
Some recent experiments with the virus of pneumonia in spu- 
tum (Bordoni Ufferduzzi, Centralblat f. Bakteriologie, X., p. 305.) 
indicate attenuation after twelve hours' exposure in a dessicated 
state to sunlight. 
With these attestations of its germicidal powers, let us consider 
the method of its application. For practical purposes the heat- 
rays can be filtered out of a beam of sunlight with a flat cell 
filled with a strong solution of alum, the most elegible ather- 
manous material; and concentration of the light may be increased 
about twenty fold before the painful effects of heat-concentration 
are experienced. (A common whisky flask free from flaws, filled 
with alum solution and a lens, such as is sold for examining pho- 
tographs, will serve for all minor purposes.) This degree of con- 
centration I have frequently employed on boils, warts, ringworms 
and the like, with instructive results ; although they are too in- 
exact from the trifling nature of the cases and from the absence 
of control experiments to describe them in detail. 
I have secured distinct escharotic effects from a greater degree of 
concentration, although cosmoline would barely melt at the focus 
of the lens, a temperature of about 125° F.; and that effect was 
attained in two cases with a slight pricking sensation hardly 
amounting to pain, although the entire thickness of skin was 
reduced to a whitish, pulpy mass. This agrees with the Russian's 
observation already referred to, and with Dr. Fryer's experience, 
in which the simple burning-glass was used without anaesthetizing 
the patient. The pain after a time was not complained of, not- 
withstanding the high temperature developed at the focus of the 
lens. He records as the principal objections to the treatment the 
unpleasant appearance of the operation and the odor and the 
smoke from the burning flesh. 
' Since 120° F. is about the limit of usual toleration of moist 
heat, and since 145° F. dry heat produces nearly intolerable 
pain in one minute and in ten minutes causes quite active hyper- 6 
semia, it is plain that the concentrated light, minus its grosser 
heat, is both amesthetic and escharotic, the last in a mild degree. 
In considering the former property, some allowance must be 
made for the effect of dessication, which, although hindered 
somewhat in this case by the transudation of serum, has an ad- 
mitted anaesthetic effect. The latter property manifests itself in 
in the severe blistering of the skin at elevations above the snow 
line and in small boats on the water in the tropics, being much 
severer in the early and in the late hours of the day, from the ob- 
lique position of the sun and the greater consequent reflection 
of its rays from the surface of the water. 
It is obvious that light will have its application almost confined to 
parasitic affections, if its action be shown to be sufficiently pow- 
erful to destroy the parasites and at the same time reasonably in- 
nocent to the tissues affected. If penetration to any degree be 
admitted, concentration may increase it to any desired extent. 
The destructive action of the heat may be removed as indicated 
above by athermanous substances, or it may be neutralized in 
situ, so to speak; for instance, with a spray of liquified carbonic 
acid gas. 
In many cases the associated heat may be advantageously re- 
tained, as when a large amount of tissue is to be destroyed. This 
form of cautery is said by Dr. Fryer, hereinbefore mentioned, to 
be followed by unusually slight inflammatory reaction, which 
might have been anticipated from the perfect disinfection of the 
eschar, and from the fact that it contains no residual chemical 
for absorption and for further local irritation-not an inconsider- 
able advantage where much destruction of tissue is necessary. 
Dr. Fryer has cauterized several square inches at a sitting, but 
he thinks the number should not exceed five. 
I should upon favorable occasion employ light with any desir- 
able modifications in the treatment of epithelioma, of whose infec- 
tious character I entertain no doubt ; and in the matter of pre- 
ferance to the knife I should have much good company. I should 
employ it instead of Kraske's incisions in the surgical treatment 
of erysipelas and test, with no ordinary interest and hopefulness, 
its ability to disinfect the localized lesions in man of anthrax, 
of chancroid, of diptheria, of tetanus, and of the infective gran- 
ulomata.