4 TuLKj on Cleaning and Preparing Diatoms, 
'The Theory and Use of Hadley's Quadrant Explained;' 
'The Nature and Construction of Solar Eclipses;^ 'Optical 
Essays on Curious Subjects;' 'The New Art of Surveying 
by the Goniometer ' The Principles of Pumpwork Ex- 
plained ' The Young Gentleman and Lady's Philosophy/ 
1759; 'A New Treatise on Perspective;' ' System of Optics/ 
1740; 'Logarithmologia,' 1740; 'Philology and Philosophical 
Geography/ 1759; 'Philological Library;' 'Philological 
Grammar;' Description of both Globes, the Armillary 
Sphere/ &c. ; ' Description of his newly invented Pocket 
Reflecting Microscope ;' ' Bibliotheca Technological 
This list is taken partly from the works themselves, in 
which there are frequent advertisements of his publications, 
and partly from summaries in various biographical accounts 
of Benjamin Martin. 
On Cleaning and Preparing Diatoms. 
By J. A. TuLK. 
Believing that a short description of the method of 
'' Cleaning and Preparing Diatoms for Preservation/' which 
I have found advantageous, may be of some service to those 
who are unacquainted with and about to commence the 
practice of that art, I am induced to record it ; and if it be 
found to lighten their labours, and to produce the satisfactory 
results I anticipate, my object will have been accomplished. 
It is unnecessary to state where to look for diatoms, as that 
has been sufficiently pointed out by Professor Smith, in his 
work on the 'British Diatomaceae,' by Dr. Arthur S. Donkin, 
in the sixth volume, ' Trans. Mic. Soc. ;' by the editors of the 
' Micrographic Dictionary ;' by Mr. Ralph, in the fourth 
edition of ' Prichard's Infusoria ;' by Mr. Roper, in the 
'Trans. Mic. Soc.,' vol. ii; by Mr. Tomkins, in 'Recreative 
Science,' vol. ii ; by Mr. Tuffen West, in ' Recreative Science,' 
vol. i ; and by many other experienced writers, who, to- 
gether with the above-mentioned gentlemen, have nearly ex - 
hausted the subject. 
I will, therefore, commence with describing, as briefly as 
I am able, a plan for collecting, cleaning, and mounting a 
fresh-water gathering, taken from off the mud of a road-side 
ditch ; and I may remark that any other description of 
gathering, guanoes and fossil deposits, may be cleaned and 
