Intelligence and Miscellaneous Articles. 309 



may differ in denomination, or as the ship's magnetic polar axis may 

 happen to lie over to starboard or port. 



As an objection might be made to deductions from experiments on 

 simple individual bars or plates of iron being applied to the case of 

 iron ships built up of thousands of pieces, I have repeated the expe- 

 riments, substituting for an entire plate or bar of iron a plate about 

 18 inches long and 3 broad, made up of numerous separate plates, 

 and combined in the manner of the plating of iron shijis. The 

 compound or combined plate of some eighteen or twenty pieces 

 yielded, under percussion, vibration or bending, results precisely 

 similar to those obtained by the use of single plates or bars. 



XXXIX. Intelligence and Miscellaneous Articles. 



EXAMINATION OF THE GREEN MATTER CONTAINED IN GREEN 

 INFUSORIA. BY THE PRINCE OF SALM-HORSTMAR. 



IF the green Infusoria of large ponds be collected upon a filter, then 

 extracted with alcohol whilst fresh, and the green extract eva- 

 porated to dryness at a temperature of about 104° F., the body 

 obtained has the following properties : — 



1. When slowly heated upon platinum, it does not fuse, but soon 

 evolves vapours (not smoke) which possess the peculiar odour of 

 ponds, whilst the greater part of the mass is volatilized. The pro- 

 duction of vapour then ceases, and a small brownish residue is left, 

 •which, however, is also slowly volatilized at a temperature below that 

 at which the platinum becomes red-hot. No carbonaceous residue 

 is left. 



2. It dissolves readily both in alcohol and acetic sether. 



3. It dissolves in hot water with a yellowish-olive colour; the 

 ■water first becomes milky. 



4. It dissolves in ammonia with a yellow colour. 



5. It is soluble with a greenish-yellow colour in solution of pot- 

 ash, and the solution shows a black stripe in the red of the spectrum, 



6. The alcoholic solution has no reaction upon litmus. 



It is consequently neither a wax-like body nor chlorophyll ; for 

 chlorophyll extracted !)y alcohol from freshly- dried leaves of Lolium 

 perenne and evaporated at 104° F. until no more fluid is present, 

 forms a sticky u.a.is which does not dissolve in water, ammonia, or 

 soli;' on of potash. Its behaviour when heated in a platinum cruci- 

 ble is the same as that of the green of the Infusoria. 



The two alcoholic solutions are very different in colour when 

 freshly prepared ; that of chloroiihyll from grass is emerald-green, 

 that from the Infusoria olive or bottle-green. 



Angstrom's exact optical investigations of the two substances had 

 also presupposed their distinctness. — PoggendorfF's^nna/e«,vol.xciv. 

 p. 46G. 



