ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
341 
a vertical triangular box, from winch extends a long triangular ratchet 
bar ; at the upper end of this bar a rotating brass head is fitted ; this 
holds the trunnions of the telescope. The weight of this triangular 
ratchet bar, together with that of the telescope, is counterpoised by 
three weights attached to catgut lines passing over three pulleys at the 
top of the triangular box. The great focal length of the telescope 
renders it necessary that its point of support should be considerably 
raised above the level of the ground. 
The object-glass is still in excellent condition, and it yields a sharp 
and well-defined image. 
B. Technique.* 
(1) Collecting: Objects,. including- Culture Processes. 
Method for Making the Three Principal Artificial Media.f — Mr. 
H. W. Hill, in the following table, gives directions for making nutrient 
media based on the recommendations of a bacteriological committee. 
Boil 30 grm. thread agar in 
1 litre of water for half an hour. 
Make up loss by evaporation to 
a weight of 1000 grm. - Cool and 
solidify. 
Nutrient Broth. 
N UTRIENT 
Gelatin. 
Nutrient Agah. 
1. Infuse lean meat twenty hours 
with twice its weight of dis- 
tilled water in refrigerator : 
Say 1000 grm. meat. 
2000 grm. water. 
2. Make up weight of meat in- 
fusion (and meat) to origi- 
nal weight by adding water, 
i.e. to 3000 grm. 
Infuse lean meat 20 hours with 
its own weight of distilled 
Ditto. water in refrigerator. 
Say 1000 grm. meat. 
1000 grm. water. 
Ditto. Ditto, 
i.e. to 2000 grm. 
3. Filter infusion through cloth Ditto, 
to remove meat. 
Ditto. 
4. Titrate and record reaction of 
filtrate. Ditto. 
Say reaction + 2 • 2 per cent. 
Ditto. 
Say reaction +4*2 per cent. 
5. Weigh infusion. 
Say 1800 grm. 
Ditto. 
Ditto. 
Say 900 grm. 
6. Set infusion on water-bath, keep- 
ing temperature below 60° C. Ditto. Ditto. 
7. Add peptone, 1 per cent., 18 grm. Ditto, and Add peptone, 2 per cent., 18 grm. 
Add salt, 0 ’5 per cent., 9 grm. sheet gelatin, Add salt, 1 per cent., 9 grm. 
10 per cent. 
180 grm. 
* This subdivision contains (1) Collecting Objects, including Culture Pro- 
cesses; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 
(4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, &c. ; 
(6) Miscellaneous. t Journ. Applied Microscopy, ii. (1899) pp. 301-4. 
