35 
named comparisons. Hence, with a view of determining the relative 
toxicity of the compounds already compared by the blood-pressure 
method, the following experiments were undertaken. The test object 
chosen is the ordinary white mouse, reared in our own mousery under 
conditions well under control. As a rule these mice when placed in 
individual jars on a diet of oats and water lose in weight, but after 
the first day, upon becoming accustomed to their new surroundings, 
return to normal. Generally on a given day the mice were brought 
into the preparation room, weighed, and on the second day weighed 
again, whereupon the dose was calculated and unless otherwise 
stated the solution made up and injected at once. All mice were 
injected tailward underneath the skin of the back. The sjHnge 
used was calibrated in 0.05 c. c., standardized, and fitted at first with 
a steel needle. Since this needle, especially if tarnished, decom- 
posed the solutions, a platinum-iridium needle was substituted. 
The phenomena accompanying subcutaneous injections of this 
nature may be summarized as follows : Soon after being released the 
animal seeks a corner of the jar, under the chaff, or at once stretches 
itself lengthwise upon the belly with hind feet directed backward 
and planta turned upward. The favorite position is to lie upon the 
cool, moist oat jar with head downward, breathing at first very 
rapidly and later more or less irregularly. In this stage the animal 
may be highly excitable, its reflexes being probably intensified not 
only by the injected material but also by the fear aroused by the 
smarting of the needle’s prick and by fright from handling. In case 
the dose is rather large the bulbus is protruded, and the glands of 
the eye are usually stimulated to excessive secretion. 
In some mice thirty to sixty mintues after injection a small opales- 
cent ® disc appears in the eye. This later becomes opaque white and 
may be confined to onl}^ one or extended to both eyes. The phenom- 
enon seems to be one of the lens and resembles cataract. In this 
respect it differs from the opaquing observed in the eyes of frogs, 
for in the latter case I have proved that the initial opaquing is due to 
coagulation of the outer membranes of the bulbus and that it can be 
removed by stripping off this membrane, whereupon the eye becomes 
perfectly clear. In the eye of the mouse the opaque disc, examined 
with a magnifying glass, seems to be underneath the cornea, of the 
size and position of the lens. The following protocol is taken from 
a mouse injected with arterenol and is typical of the cases observed 
with natural 1- and synthetic dl-adrenalin : 
Mouse 324, weight 22.22 gm. March 15, 12.20 p. m., injected subcutaneously 
0.44 c. c. (0.88 mg.) arterenol hydrochloride. 
“After this section had been written I noticed in a recent article by Emmert a 
reference to his observation of what seems to be a similar phenomenon. 
