IN THE ANIMAL KINGDOM. 11 



the blood of Helix aspersa is bluish-white by daylight and of a purplish 

 tinge by gaslight; he found that the blood of Limnceus stagnalis on exposure 

 to the air assumed a bluish-white color and that the blood of Paludina 

 vivipara is of a blue color. None gave absorption bands. 



Griffiths (Compt. rend. soc. biol., 1892, cxiv, 496, 840, 1277; cxv, 669) 

 made elementary analyses of the hemocyanin of the bloods of Homarus, 

 Sepia, and Cancer, which he obtained by precipitating with magnesium 

 sulphate, dissolving the precipitate in water, again precipitating with 

 alcohol, and finally drying in vacuum at 60. Fre'dericq, Krukenberg, 

 and Henze state that magnesium sulphate causes either little or no pre- 

 cipitation of hemocyanin. This statement is opposed by Griffiths, Couv- 

 reur (Compt. rend. soc. biologic, 1902, LIV, 125), and Halliburton (Journal 

 of Physiology, 1885, vi, 300). The latter states that "just as precipitation 

 by heat is slow, so is also precipitation with salts ; to effect complete satura- 

 tion with either of the above-mentioned salts (magnesium sulphate or 

 sodium chloride) the serum must be shaken in an engine for 12, 24, and in 

 some experiments 36 hours, with the finely powdered salt." Probably 

 the difference in the results of Griffiths, Couvreur, and Halliburton from 

 those of Fre'dericq, Krukenberg, and Henze may be explained by differ- 

 ences in species and freshness of the blood and other incidental conditions. 



Griffiths' analyses showed 



the mean being 



C54-155H7. 095Ni6-268So-647 



The empirical formula he calculated to be 



Interesting in this connection is his analysis of the brown coloring matter 

 of the blood of the lamellibranch Pinna squamosa. This substance he 

 describes as a body very closely related to hemocyanin, but in which there 

 is manganese instead of copper. Krukenberg (loc. cit.) had already found 

 that the blood of this animal was rich in manganese. Griffiths named this 

 pigment pinnaglobulin. His elementary analysis showed 



C55-07H6-24Ni6-24So-8l021- 



and the empirical formula he calculated to be 



In the blood-ash of Pinna he found manganese but not iron, while in that of 

 Sabella and Sipunculus he found iron but not manganese. The centesimal 

 analyses and empirical formulas of hemocyanin, pinnaglobulin, echinochrome, 

 chlorocruorin, hemerythrin, and hemoglobin are given by Griffiths as follows: 



TABLE 2. Empirical formulas of certain respiratory substances, according to Griffiths. 



Hemocyanin ........................... Cgs? H^gs N 2 23 Cu 84 025& 



Pinnaglobulin ......................... C 72 9 H 98 5 Ni 8 s Mn S 4 O 2 io 



Echinochrome ......................... 102 HQQ Ni2 Fe 82 Oi2 



Hemerythrin .......................... 427 H 7 ei NJSS Fe 82 153 



Chlorocruorin .......................... Cgeo Hs45 ^H3 Fe 83 Oie? 



Hemoglobin ........................... Ceoo H 9a o N 1M Fe 83 Oi 79 



