ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
553 
holes, each 2 cm. in diam. and 3 • 5 cm. deep, for reagent phials. The 
first groove is used for razor, and the second for pencils, pipette, forceps, 
&c. The block is -easily 
made, costs very little, is 
very neat in appearance, 
and convenient in work.” 
Microscopic Diagnosis 
of Citric Acid in Plants.* 
— M. E. Belzung states 
that, according to Schultze, 
citric acid may be recog- 
nized in the ripe seed of 
Lupinrn luteus by treating 
the seeds with alcohol, 
evaporation, and treating 
the residue with water; 
from this solution citric 
acid can be separated. 
The author, however, endeavours to diagnose the acid by means of the 
formation of citrate of calcium. Young plants were grown in a weak 
solution of nitrate of calcium, sections of the plant were made, and 
examined microscopically ; after a short time, numerous acieular crystals 
appeared, which were found to be those of citrate of calcium. 
Artificial Preparation of the Sphseroliths of Uric Acid Salts-t — 
Herren W. Ebstein and A. Nicolaier say that if some uric acid be dis- 
solved on a Microscope-slide in a dilute alkaline solution, and watched 
with the Microscope, there is, after slight concentration, a formation of 
round particles of urates varying in diameter from 2-100 //. These are 
mixed with needles, either singly or in bundles. As solvents, sodium 
hydroxide, potassium hydroxide, lithium carbonate, borax, ammonia, 
and piperazine were used ; the best results were obtained by using the 
uric-acid sediment from human urine. 
With the polarizing Microscope between crossed nicols the sphaero- 
liths showed a right-angled, black interference cross, the arms of which 
lay parallel to the polarization planes of the nicols, and, concentric with 
the middle point of this cross, coloured interference rings were seen. 
Similar sphaeroliths were obtained with sodium hydrogen carbonate, 
so that they may consist either of acid or normal urates. 
The interest of such an observation, as bearing on the formation of 
urinary calculi, is pointed out. 
* Journ. de Bot. (Morot) v. (1891) pp. 25 9 (3 figs.). 
f Virchow’s Arcliiv, 123, pp. 373- G ; see Journ. Chem. Soc. Lond., cccxliii. (1891) 
pp. 760-1. 
Fig. G9. 
2 Q 
1891. 
