688 RECORD OF CURRENT RESEARCHES RELATING TO 



made with the greatest exactness, and by means of the most perfect 

 objectives. They were drawn by himself or under his eye, and 

 retouched by himself or Herr Grunow, who has also drawn the plates 

 of some of the groujis. The power used Avas one of 900 diameters 

 for the easier forms, and 1500 for the most difficult, and the drawings 

 •were then reduced one-third by heliography. Owing to the care that 

 has been taken, the excellence of the objectives, and the use of helio- 

 graphy, he thinks there can be no doubt as to the species figured. 

 " Unhappily one cannot say as much for the greater part of the 

 drawings of diatoms published during the last fifty years, a great 

 part of which are enigmas more or less insoluble even with the aid of 

 authentic specimens." 



Dr. Van Heurck's botanical museum contains the original types 

 of the principal diatomographs — Kiitzing, Walker- Arnott, Eulenstein, 

 De Brebisson, &c. 



New Deposit of Diatomaceous Earth. — At the May meeting of 

 the San Francisco Microscopical Society, the President announced, 

 that more of the celebrated Santa Monica diatomaceous earth, or 

 some similar to it, had been discovered. The deposit is about 

 seventy miles from the spot where the original piece was first dis- 

 covered by Mr. T. P. Woodward, two years ago. The present theory 

 is that the former piece became detached from the main deposit, 

 was washed into the sea, and then carried by the tide to the shore 

 on which it was found. Professor H. L. Smith, of Geneva, N.Y., 

 reported by a letter read by the President that he had tried the 

 deposit and found it so rich and so nearly like the " Santa Monica," 

 that he desired a quantity. Mr. Norris and ex-President Hyde had 

 also made a careful examination of the material, and the former pre- 

 sented a mounted slide which showed forms of great beauty and fully 

 as rich as the original of two years ago. 



It is added that " scientists all over the world, it is to be hoped, 

 can now be supplied with this very interesting material, for which 

 they have been so anxious." 



Preservation of Solutions of Palmelline.* — Dr. T. L. Phipson says 

 that the solution of palmelline obtained by allowing cold water to stand 

 for a day or two over the air-dried plant (Palmella cruenta), as described 

 by him,"!" like all solutions of albuminoid substances, is very subject to 

 decomposition, and at temperatures of 75°-80° F. putrefaction sets in 

 rapidly. The beautiful rose and yellow dichroic tint of the solution 

 becomes paler, and finally disappears, whilst the liquid takes a strong 

 ammoniacal odour and swarms with Bacterium, Vibrio, and Spirillum. 

 The latter are not easily to be distinguished (except by their small 

 size and that their motion is more rapid) from the Spirillum which is 

 present in the blood in cases of relapsing fever, during the pyrexia 

 only, disappearing as the temperature of the body falls. 



Various methods of j)reserving the liquid in question without alter- 

 ing its composition and ojitical j^roperties were tried. Exclusion 

 fi-om air and light were only partially successful for short periods. 

 * ' Chem. News,' xli. (1880) p. 21G. f See this Journal, ante, p. 319. 



