Vol. XVII 
i Correspondence. 319 
of teaspoonfuls were injected into the viscera of the birds to be experi- 
mented upon and, as the stomachs were full of fish, about half a tea- 
spoonful was sent down the gullet, the throat being then plugged with 
cotton. Also on the afternoon before leaving I pulled the skins off some 
Puffinus creatopus and P. griseus that were still left, put some cotton 
dampened with the solution inside the skins, after they were turned back 
into natural shape again, and rolled them up in newspaper to be carried 
in a valise. Two days afterward both the birds in the flesh and the 
treated skins were found to be in good condition. The former were 
skinned and put up three days after having been shot, while the latter 
were scraped and finished as time permitted, the last ones having been 
five days in this condition. These were kept in a tight box containing a 
layer of damp sand upon the bottom and except for a slight hardening of 
the tissues were in sufficiently good shape to make a very fair skin. 
These results exceeded my expectations, and further experiments dem- 
onstrated the fact that the use of formaldehyde places the collector 
in a comparatively independent position in regard to the number of 
specimens he may collect in a day, as with its aid he can keep a number 
in good condition until time admits of preparing them for his collection. 
I came across an old-fashioned veterinary hypodermic syringe at a low 
figure, and this, with a bottle of saturated solution of formaldehyde 
accompanies me on all my expeditions. ‘This syringe holds one tea- 
spoonful, and this is sufficient for a bird as large as a Partridge. The 
sharp needle is punched into the abdomen in one or more places, a few 
drops are sent down the throat of a bird to be saved, and if to be kept for 
some days a little is injected into the brain by opening the bill and forc- 
ing the needle upwards and backwards between the eyeballs. 
In place of a regular hypodermic, a common glass syringe, or even an 
eye dropper, can be made to answer, especially if the end is heated and 
drawn out to a sharp point as in an egg-blower. 
The amount injected and the strength of the solution must depend 
upon the size of the bird. Formaldehyde comes in saturated solution of 
nominally 40%, while from 4% to 10% is what may ordinarily be used. 
For birds up to the size of a Partridge, 4 % is sufficiently strong, from this 
to the size of a Duck 8 or 10%, and for Geese and very large birds a com- 
paratively smaller amount of the full strength seems more satisfactory 
than a larger amount of a weaker solution. It is well to avoid, as far as 
possible, having one’s hands-come in contact with the strong solution as 
this is apt to harden the skin of the fingers and cause cracks into which 
arsenic may be introduced. Upon the basis of the original solution being 
40% it is a simple matter to approximate any desired strength by mixing 
in a separate bottle one part of the solution to so many parts of water 
roughly estimated. 
The strength and amount necessary for different birds will soon be 
learned with a little practice. If too much or too great a strength is used 
upon small birds the body becomes more or less hardened and dry, mak- 
