2l8 REPORTS OF INVESTIGATIONS AND PROJECTS. 



preliminary account of this work was presented to the Physical Society at 

 the December meeting, 1906. 



(3) Cathodo-luminescence of Sidot blende. The spectrophotometric study 

 of the luminescence of Sidot blende under the influence of cathode rays has 

 been begun, but this work is barely under way. 



PHYSIOLOGY. 



Loeb, Leo, University of Pennsylvania, Philadelphia, Pennsylvania. Grant 

 No. 444. The toxic action of the poison of Heloderma susf\ectiim. $1,000. 

 A considerable number of experiments on the venom of Heloderma have 

 been carried out in order to determine some of the general properties of 

 the poison and the susceptibility of different species of animals, especially 

 certain conditions of natural immunity and means which permit the in- 

 crease of the secretion of the venom. Among the facts ascertained so far 

 it may be mentioned that the secretion of venom is increased by injection of 

 pilocarpin in a similar way as other glandular secretions. The fatigue of 

 the gland after repeated injections has been investigated. The immunity 

 of Heloderma towards its own poison as well as its susceptibility towards 

 certain snake venoms has been ascertained. It is expected that a full report 

 of the results obtained so far will be published in the near future. 



Reichert, Edward T., and Brown, Amos P., University of Pennsylvania, 

 Philadelphia, Pennsylvania. Grant No. 188. Research on the crystal- 

 lography of hemoglobins. (For previous reports see Year Book No. 

 3, p. 134, and Year Book No. 4, p. 262.) $1,000. 



Since receiving the grant of the Carnegie Institution of Washington, in 

 April, 1904, work upon the crystallography of hemoglobins has been actively 

 prosecuted, whenever the weather and the supply of material permitted. 

 Methods of promoting or retarding or otherwise influencing crystallization 

 have been originated or improved. By retarding crystallization, measurable 

 crystals have been produced from bloods, in which, on account of their rapid 

 formation, it has heretofore been impossible to develop them. By methods 

 which promote crystallization it has been found possible to produce crystals 

 from bloods not heretofore crystallized. Through original processes we have, 

 in specimens of certain species, been enabled to crystallize at will one or 

 another of the several forms of oxyhemoglobin present. 



Crystals from the bloods of 100 species have been studied. The photo- 

 graphic records of these crystals of oxyhemoglobin, hemoglobin, the "methe- 

 moglobins," etc., will be found in over 1,500 negatives that have been pre- 

 pared, and from these a selection (probably one-fourth) will be made for 

 illustration of a memoir. Crystallographic characters have also been re- 

 corded in sketches, records of measurements, and crystallographic notes, 



