190 Miscellaneous. 



and it will exert so powerful an oxidizing action, that in a few 

 moments a carbonaceous material as black as ink will become per- 

 fectly dean and colourless. Nothing now will remain to be done 

 l)ut to wash oft' the acid, which is best done by the addition of water 

 and repeated decantations. I also would advise that the materials 

 thus cleaned should not be dried, but should be kept in bottles with 

 n little alcohol, which ]>revonts their telting together, and does not 

 allow the growth of the byssoid ])lants which often develope in water. 

 It is necessary to ca\ition those not familiar with chemistry against 

 using the chlorate of potnssa with sulphuric acid in any otiier way 

 than above directed, as violent and dangerous explosions might re- 

 sult. The ])roces3 as above given is perfectly safe and very effective. 

 — fiiUimuiis Journal, Jannarv 1S5G, p. 14.">. 



New method of D'n^'oitetindnty masses of Fossil Diatomaccae. 

 By Prof. J. W. Bailey. 



Many masses of fossil Diatomacece are so strongly coherent, that they 

 cannot be diffused in water (for the ])urpose of mounting in balsam) 

 without a degree of mechanical violence which reduces to fragments 

 many of the most beautiful and interesting forms. This is particu- 

 larly the case with some specimens from the "infusorial deposits" of 

 California. Some of these I endeavoured to break up, by boiling in 

 water and in acids, and {\lso by re|)eated freezing and thawing when 

 moistened, but without good results in either case. At last it oc- 

 curred to me that the adherence might be due to a slight portion of 

 a siliceous cement, which the cautious use of an alkaline solution might 

 remove without destroying any but the most minute shells of the 

 Diatoms. As the case aj)j)cared a desperate one, a '' heroic remedy" 

 was applied, which Avas to boil small lumps of the diatomaceous mass 

 in a strong solution of caustic j)otassa or soda. This proved to be 

 perfectly etticacious, as the masses under tliis treatment rapidly split 

 up along the planes of lamination, and then crumbled to mud, which 

 being immediately poured into a large f[uantity of water, ceased to 

 be acted upon by the alkali, and gave, when thoroughly washed, not 

 only all the large shells of the Diatoms in a state of unhoped-for 

 perfection, but also furnished abundance of the minute forms. 

 Having obtained by this method highly satisfactory results from 

 specimens from many localities, I can confidently recommend it as 

 an addition to our modes of research. 



The following directions will enable any one to apply the yjrocess. 

 Put small lumps of the mass to be examined into a test tube, with 

 enough of a solution of caustic potassa or soda to cover them ; then 

 boil over a sjiirit-lamp for a few seconds, or a few minutes, as the 

 case may require. If the solution is sufficiently strong, the masses 

 will rapidly crumble to mud, which must be poured at once into a 

 large quantity of water, which after subsidence is removed by decan- 

 tation. If the mass resists the action of the alkaline liquor a still 

 stronger solution should be tried, as while some specimens break up 

 instantly in a weak solution of alkali, others require that it should 

 be of the consistence of a dense syrup. The mud also should be 





