Goltz Experiments

GOLTZ EXPERIMENTS (Goltz), consisted of the removal of both cerebral hemispheres of the brain together with the subcortical formations in dogs. Those formations which were not removed during the operation fell out of function due to the softening that occurred in them. The clinical picture described on the basis of careful observation is as follows: the movements and standing of such dogs were more or less correct, coordinated; when lying down to sleep, the dogs curled up into a ball; they rose and moved easily, almost with normal speed; in the near future after the operation, muscle wasting developed. Sensitivity was reduced; the dogs did not react to weak stimuli; muscular sense was not disturbed (they placed incorrectly placed legs back in a normal position). There was a disturbance of all sensory organs—a complete loss of olfactory sensations; gustatory, auditory, and visual sensations were strongly dulled but not destroyed: very strong light stimuli caused a pupillary reaction, the animal even turned its head away; when moving around the room, the dog did not bump into furniture and avoided a burning burner: it did not find food lying even nearby due to the loss of the sense of smell and visual perceptions; the animal did not recognize visible objects and heard sounds and did not react to them as before. Appetite remained good, the intake of food and drink was more or less correct, self-sufficient, but it was necessary to bring food into contact with the muzzle; the dog itself did not find food. The gastrointestinal tract worked perfectly correctly. Regulation of body temperature was sufficient, the reaction to external temperature was lively: in the cold the dog shivered, in the heat it often breathed, stuck out its tongue. Sleep was good, its duration was greater than in normal dogs. The intellect of the animals was very reduced; they became after the operation indifferent to everything around them, little mobile, they lacked understanding and recognition of external stimuli and a correct reaction to them. Perceptions were very limited, as were their evaluation; the dogs could not learn useful actions for them. The emotional sphere seemed to have suffered less; when the dog was teased, it tried to bite, the intonation of the voice indicated some emotion; during hunger, restlessness was observed, but, on the other hand, the dog did not show any pleasure or joy when fed. With his experiments, Goltz wanted to show that the life of an animal can be maintained more or less correctly without the participation of the brain. But the operated animal became mentally deficient, turned into a reflex automaton, acting under the influence of only external stimuli; reflex actions caused by stimulation could not be changed or weakened due to the absence of regulators in the form of cerebral hemispheres.

E. Kononova. (Holzknecht), released by G. (1902), was the first quantum-metric device in roentgen therapy. The chromoradiometer consisted of special transparent tablets, the composition of which the inventor keeps secret. These tablets, after being illuminated by X-rays, changed their color and became darker. The greater the amount of X-rays acting on the tablet, the darker it became colored. The color of the illuminated tablet was compared with a special scale of shades from 3 to 24 N (N is a unit of dose), and to what shade of the scale it coincided, so many N corresponded to the amount of X-rays. 3 N by this chromoradiometer caused a barely noticeable reaction on the skin of the face of an adult. G. h. was abandoned because it was not possible to manufacture tablets of equal sensitivity.

G. dosimeter. At present, the most common photo-chemical device for dosimetry in roentgen therapy is the G. dosimeter, consisting of a series of thin reactive tablets (in the form of a semicircle), glued onto cardboard strips. These tablets consist of a double salt of barium cyanide and platinum. Under the influence of illumination by X-rays, the salt loses its crystallization water, due to which the color of the tablet changes from light green to dark brown, depending on the magnitude of the dose. The shades of the tablets are compared on a scale arranged as follows: the scale (see figure) represents a board on which divisions from 0 to 32 N are applied. Next to the divisions a transparent celluloid plate is fixed, the color of which changes from light to dark brown from top to bottom. Along the board moves a special clamp, into which from the side an illuminated tablet is inserted, and from above, under the celluloid plate, an unilluminated one. The clamp is moved from top to bottom until the shades of both tablets coincide and on the scale is marked, how many N this corresponds to.

When using the G. dosimeter, a tablet protected from the action of daylight is placed on the illuminated surface, and the shades are compared in the light of an electric carbon lamp. 5 N of medium-hardness rays on this dosimeter correspond to an erythema dose. The G. dosimeter is convenient in that it can be used to measure parts of the erythema dose. However, its readings are correct only for medium-hardness rays, and therefore when indicating the amount of X-rays in N units, it is necessary to indicate the quality of the rays as well. A table is attached to the G. dosimeter, indicating dosing for various diseases, fully suitable for practical work.