Answers to Queries. 135 
is retarded, and ultimately the fire becomes extinguished, not on 
account of the direct action of the sun, but because the oxygen of 
the air cannot properly combine with the carbon and hydrogen of 
the fuel. If the sun had the power to put out the fire, then a 
Bunsen burner must be extinguished in full sunlight. This is not 
the case, although the flame is absolutely invisible. It will still 
burn, boil, or bake, any article placed in it, and indeed in all 
respects act as an ordinary flame except in the matter of its 
invisibility. J. W.G 
[Will some other correspondent also answer this query ?— 
L:ditor. | 
368.—Spathe.—B. O. B. is much obliged to W. A. Lett for his 
answer to this question, but at the same time wishes to point out 
that the definition give a Spathe, is a large bract— 
involves too much. By this definition any /arge bract would be 
properly termed spathe. As, for example, the glumes of grasses, 
the large bracts of the Atripler, the red bracts of the Pointsettia, 
many other Euphorbiacez, together with numerous other 
examples, which perhaps would illustrate the point far better. 
Many of these may be doubtful cases, but some of them no 
botanist could think of calling spathes. My difficulty was this— 
Gray defines a spathe as “a large bract or a pair of bracts 
enclosing a flower cluster.” ‘Thomé says a spathe is the envelop- 
ing bract of a spadix ; many other botanists defining it in the same 
way, indeed, some reasoning in a circle say that a spadix is a 
cluster of flow ers, enveloped by a spathe, and that a spathe is the 
enveloping bract of the spadix. Hooker again terms the envelop- 
ing bract of the snowdrop a spathe, and as a snowdrop is neither 
a spadi nor a flower cluster, it appears to me that a more rigid 
definition of “spathe” is requisite. Mr. Lett’s is too broad for 
scientific purposes, and many others are too vague. BO: B, 
368.—Spathe.—A large coloured bract, enclosing the inflor- 
escence, as in the Trumpet Lily, is called a spathe (Lat., spatha, 
a spatula, etc.) A flower spike of this kind, enclosed in a spathe, 
is distinguished as a spadix—e.g., Arum and Richardia. V. A. L. 
370.—To Increase Specific Gravity.—A solution of ammonia, 
s.g. 884, contains, according to Carius, 36 per cent. of ammonia 
gas at 14° C,, and a solution of s.g., 8911 contains 32°8 p.c. of 
ammonia gas. Other observers give somewhat different results. 
A table in Attfield’s chemistry gives 38°118 and 34°4 respectively, 
being in the one case a difference of 3°2 and in the other a 
difference of 377) pen cent. 
I cannot find any table except Dalton’s giving the strength of 
880 ammonia, and as he gives this as 27°3 per cent he is probably 
wrong. Reasoning from Carius the s.g. of 880 would contain 38:8 
