RAINEY, ON CARBONATE OF LIME GLOBULES. 25 



deposit around them partially disappears, leaving only- 

 minute crystals of oxalate of lime. The disappearance of 

 this matter is best seen by examining it from time to time 

 where it exists between two globules, and noticing particu- 

 larly the amount of diminution during stated intervals. 

 As the globules increase in size the crystals also increase, but 

 more slowly than the globules, so that one part of this 

 amorphous matter appears to be attracted by crystals and 

 another by the globules, a fact which seems to indicate that 

 each has a kind of specific attraction, exerted at sensible 

 distances. As the globules get larger, the carbonate which 

 their surface receives is clear, being probably now the fresh 

 carbonate attracted by them, without first collecting in suf- 

 ficient quantity to appear in an amorphous shape. See 

 fig. 2, which shows two globules, with the amorj)hous 

 matter between them, and fig. 3, the same two globules 

 examined a week later, from between which all this 

 matter has disappeared. During this interval both globules 

 had increased in diameter. If globules form where there is 

 no amorphous matter, as on the cover of the cell, they have 

 no granular matter in the centre, but are clear throughout. 

 In some cases, a portion of the granular matter remains 

 attached to the floor of the cell, without passing into globules 

 or dumb-bells. The form of the globules is very much influ- 

 enced by that of the surface of the glass. If this be rendered 

 rough, and thus the points of attraction be increased, the 

 number of globules will be increased accordingly, but their 

 size diminished ; but if the surface be coated with shell-lac, 

 a repellent action will be exerted upon the solution of gum, 

 and globules of a larger size will result ; lastly, if the car- 

 bonate be formed only in very small quantities, it will be 

 attracted by the glass in minute but separate globules, and 

 the interstices between them becoming gradually filled up by 

 subsequent additions, a film of coalesced globules will be 

 formed, covering the surface of the slide, similar to some 

 forms of shell-tissue. All the appearances above described 

 are best seen when the solutions of gum are as thick as 

 possible, in which case, as before stated, the time required 

 for their production will be slow. I have not noticed in 

 those globules which have an amorphous nucleus that this 

 nucleus has, in three or four months, sufifered any visible 

 change, either in size or appearance. In some globules the 

 central part is made up of an aggregation of small globules, 

 whilst the peripheral one is more or less clear and lami- 

 nated, as represented in fig. 4. These bear a strong re- 

 semblance to the otolithes of small fishes in an early stage of 



VOL. I. NEW SER. C 



