* 
memasoes 
INORGANIC SALTS TO MONILIA SITOPHILA 277 
most striking point in this table is the high toxicity of zinc in 
starch. In this medium it is more toxic than any of the other’ 
salts tested except mercuric chloride. This observation suggests 
that the value of zinc chloride for preserving wood from decay is 
based on a similar relation between zinc and the cellulose of the 
wood. Starch and cellulose are much alike chemically and it is 
rather to be expected that a salt which is extremely toxic in starch 
media would also be very toxic in cellulose. The toxicity of zinc 
chloride in saccharose and glucose is practically the same and is 
greater than in lactose. In lactose, zinc is more than fifty times 
less toxic than either copper or iron. The average limit concen- 
tration is .0022 molar. 
TABLE IX 
THE TOXICITY OF COBALTOUS CHLORIDE IN SACCHAROSE, GLUCOSE, LACTOSE, STARCH, 
AND PEPTONE MEDIA 
Saccharose 5% | Glucose 5% Lactose 5% | Starch 5% | Peptone 5% 
eee ed ‘esos iamaipenilisdiptsamoey hepa eeepc |W citation lgeineilainsteieinnitee dancin: 
x.M. wth 
Oa. Con.| GRE Ga, Cone| pet" Ga Cone. he) San engin alee 
et | 5D 3 Day 3 | CoC 3 Days} CoCls 3 Days} CoCl, | 3 Days | CoCl, | 3 Days 
-00050! a 00050 -_ .000080 — |.00080| — |.0400; — 
0040 = 00040 - .000070 00070 — | .0350 — 
00030! — 00030 a 000060 — |.00060; + | .0300 _ 
00020 a 00020 — | .000050 — |.00050; + | .0250 _ 
0o0oro ~ oooro — | .000040 -00040} + .0200 = 
00009 + 00009 + 000030 — |.00030} + O150 a 
00008 + 00008 a | -000020 + |.00020| + |.o100; + 
00007 + 00007 + | .oo0015 + |.00020| + | 0050 o 
00006 “- 00006 + | .ooo010 + |.00009| + |.0010| + 
00005 + 00005 - .000008 a |-00008 | ui a oe .0008 be 
The influence of the different media on cobaltous chloride is 
quite marked. It is five hundred times more toxic in lactose than 
in peptone. In starch it is less toxic than in glucose or saccharose 
but more toxic than in peptone. The average limit concentration 
is .0020 molar, which shows that, on the whole, it is only a little 
more toxic than zinc chloride. The poisoning of the fungus by 
cobalt, cadmium and mercury is different from that of calcium, 
iron, etc., in that Monilia in nature probably does not come in 
contact with any but minimal concentrations of the salts of these 
metals. Its resistance to cobaltous chloride, cadmium chloride 
‘ The growth in this culture was quite lt limited: only aamall oer Gent. of the spores 
had pushed out germ t 
