FOOTE AND MOHLER: IONIZATION 435 



apex to submedian; hind wings with a subterminal maroon line shaded 

 with fuscous. The gloss on underside more of a steel color. 



Expanse: male 65 mm. ; female 74 mm. 



Habitat: Serra da Mantiqueira, Brazil. 



Type. — Cat. no. 23,349, U. S. National Museum. 



Unlike any described species. 



Actinote calderoni Schaus, sp. nov. 



Male. — Head, collar and thorax black, some white scaling on vertex; 

 a silvery shade on tegulae. Body whitish. Wings thinly scaled, 

 grayish white, the veins fuscous brown. Fore wings with short terminal 

 gray streaks on interspaces, longer above vein 5 and 6; the interspaces 

 between veins 8 and 11 suffused with gray. Hind wings with gray 

 streaks on interspaces from near cell to termen; a short streak in cell 

 before discocellular. Wings below similar; a small ochreous spot at 

 base of hind wing. 



Expanse: 43 mm. 



Habitat: Ateos, Salvador. 



Type. — ^Cat. no. 23,348, U. S. National Mjiseum. 



Received from Mr. Calderon, head of the Agricultural Laboratory 

 in Salvador, in whose honor I take great pleasure in naming this species. 



THERMOCHEMISTRY. — The thermochemistry of ionization of 

 vapors of certain compounds.'^ Paul D. Foote and F. L. 

 MoHLER, Bureau of Standards. 

 Two general types of ionization of compound molecules in 

 the gaseous phase are known. In one mode of ionization the 

 molecule preserves its general structure, simply losing a nega- 

 tive charge and becoming a positive ion. It seems probable 

 that materials capable of ionizing in this manner should possess 

 a characteristic spectrum, as for example, carbon monoxide. 



In the second type of ionization the molecule is dissociated 

 into a positive and a negative ion. Materials which are ionized 

 in this manner probably do not possess characteristic spectra in 

 the ordinary sense. Radiation of a single frequency, usually in 

 the extreme ultraviolet, may he emitted, however, when the two 

 ions recombine to form the neutral molecule. We have found evi- 

 dence that hydrogen chloride exhibits this form of ionization,^ 

 being without doubt dissociated on electronic impact of 14.0 

 volts into a hydrogen nucleus and a negative chlorine ion. 



* Published by permission of the Director Bureau of Standards. Received 

 Aug. 21, 1920. 



2 FooTE and Mohler. Journ. Amer. Chem. Soc. September, 1920. 



