232 Proceedings of Philosophical Societies. [Mancu, 
attention of philosophers, from its influence on most of the pheno- 
mena of living nature, yet it has hitherto been but little examined, 
M. Vogel has just added some experiments to those which we for- 
merly possessed. Ammonia and phosphorus, which do not act on 
each other in the dark, when exposed to the solar light disengage 
phosphoreted hydrogen gas, and deposit a black powder composed of 
phosphorus and ammonia intimately united. Nearly the same thing 
takes place with phosphorus and potash. ‘The action of the dif- 
ferent rays is not always similar; the red rays produce no effect on 
the solution of corrosive sublimate in ether, while the blue and 
complete light produce a mutual decomposition, ‘The metallic per- 
muriates are brought in the same way to the state of protomuriates, 
We have said a few words in our two last reports on the researches 
of M. Chevreul, assistant naturalist to the Museum of Natural His- 
tory, concerning soap and saponification. This skilful experimenter 
has ascertained that the action of potash on tallow produces new 
modes of combination, from which result substances which did not 
exist before perfectly formed, and two of which, margarine anda 
species of fluid oil, acquire all the properties of acids. ‘The author, 
pursuing his experiments, has ascertained that the sameeffects are 
produced by soda, the alkaline earths, and different metallic oxides, 
and that the resulting substances are in the same proportion, what- 
ever agent we have employed. Magnesia and alumina on the ¢on- 
trary merely contract a certain union with tallow, without sepa- 
rating its elements into two distinct bodies. The quantity of alkali 
necessary to convert a given portion of tallow into soap is exactly 
that which saturates the margarine and oil which the tallow pro- 
duces. Our laborious chemist has terminated his memoirs on this 
subject, by giving the capacity of saturation of margarine and fluid 
tallow, and by describing the properties of several new soapy com- 
binations which he produced by double decompositions, by mixing 
a hot solution of soap, of fluid tallow, and potash, with different 
earthy and metallic salts. Thus he has rendered the soaps, the ~ 
study of which has been hitherto neglected, almost as well known 
as the salts with which chemists have been the most occupied. 
The late M. Fourcroy made known, under the name of adipooire, 
a substance separated by means of acids from the fatty matter into 
which animal bodies buried in the earth are converted. And he 
considered it as identical with the crystalline matter in human biliary 
calculi, and with the spermaceti found abundantly in certain cavities 
of the head of the cachalot. 
M. Chevreul, led by his experiments to examine these sub- 
stances, has found that the crystalline matter of biliary calculi 
does not form soap, while spermaceti furnishes it as easily as tallow; 
but producing a somewhat different alteration in other proportions 
and with particular properties. The fatty matter of dead bodies is 
much more compound than Fourcroy had supposed, containing dif- 
ferent fatty bodies combined with ammonia, potash, and lime, It 
is a fatty matter that has already experienced the action of alkalies. 
Every person must have observed a resinous excretion of a yel- 
