Quantity Item Bausch &
desired Lomb Spencer
1 Microscope without oculars,
objectives or other a FF 44
1 Abbe condenser with two iris diaphragms
(lower and upper) 1740 300
1 Double nosepiece 1844 450
1 16 mm. achromatic objective 1021 108
1 4 mm. achromatic objective with working
distance of 0.6 mm. 1029 116
1 8 mm. achromatic objective with working
distance of 1.6 mm. 1027 112
1 10X Huyghenian ocular 1104 142
1 Mechanical stage 2116 485
1 Substage lamp with Daylite glass 1774 385-B
1 Blood counting chamber (Haemacytometer with
ruling of Thoma, Neubauer, Jappert, Brewer
or Turk) 3550 1472
6 Cover glasses for same, 20×21 mm., 0.4 thick 3595 1460
1 Howard’s mold counting chamber (with ¾ inch
inner disk) for same 3566 Special
6 Cover glasses for same 33 mm. square,
0.6 mm. thick 3598 Special
2 Cases for counting chambers 3580 1505
All analysts undertaking the Howard method should secure copies of the
two bulletins of the United States Department of Agriculture written
by Mr. B. J. Howard—Bulletin 569 on Sanitary Control of Tomato Canning
Factories and Bulletin 581, Microscopic Studies on Tomato Products.
These bulletins may be obtained from the Superintendent of Documents,
Government Printing Office, Washington, D. C., on payment of five cents
each in coin.
The details of the method as given below are reprinted from the Methods
of Analysis of the Official Agricultural Chemists as amended in 1921.