LATENT LIFE—BECQUEREL. - 545 
cent of its weight. But is it possible, without injuring its germinative 
faculty to deprive it completely of this water? Relying upon experi- 
ments by numerous investigators, particularly upon those of Schréder 
and Ewart, it was believed until recent years to be impossible to 
withdraw all the water from the protoplasm of seeds without killing 
them. In fact, Ewart had ascertained that as a general rule the 
most resistant seeds lost their vitality when their percentage of water 
fell below from 2 to 3 per cent of their weight. This had led him to 
believe that the protoplasm of seeds in its state of natural desiccation 
must have a chemical composition very different from that of pro- 
toplasm fluid in a condition of active life. According to this new 
theory the chemical composition of the protoplasm in latent life 
would correspond with the chemical equation proposed by Loew for 
certain albumins. In that instance there was obtained by poly- 
merization of aspartic aldehyde with the addition of hydrogen and 
sulphur, a proteid which finaily gave an albuminoid, whose formula, 
C12H,2AZ,350..+ 2H,0 contains 2 per cent of water. 
This conception of protoplasm from which you can not draw out 
its 2 per cent of water without decomposition, appears to me too 
simplistic or one sided, as much from the standpoint of physics as 
from that of chemistry. Besides, this formula does not include the 
greater part of the chemical elements, metals, and metaloids which 
are absolutely necessary for the constitution of the nuclei of cells and 
the formation of a protoplasm capable of life. Consequently it does 
not correspond to the reality of experimental facts, for thcugh certain 
kinds of cells do not endure a prolonged desiccation, the result is not 
the same with many other cells. 
Ewart was unable to ascertain this because he employed a very 
defective method of desiccation—that of the sulphuric-acid des- 
iccator, a process which has the great objection of often altering the 
protoplasm entirely in desiccating it. Moreover, as Maquenne, the 
learned physiologist of the Muséum d’Histoire Naturelle, has demon- 
strated, for completely drying the seeds there is only one effective 
method and that is the employment of a vacuum for several months 
at a temperature of 40° to 45° in the presence of anhydrous BaOH.! 
This process is more efficient than that of the oven at 110°C. which 
is employed in the method of dry weights. Moreover, lif, as I have 
advocated, the precaution is taken of decorticating the seeds or of 
perforating the impermeable tegument, desiccation can be obtained 
more rapidly and more actively, so that there is no releasing of 
vapor in the vacuum nor loss of weight; and, besides, the germinative 
power of the seeds thus treated is not destroyed. Maquenne has 
proved this in the case of grains of wheat, seeds of parsnip, and castor 
1 Maquenne: C. R. Acad. des Sce., t. 134, p. 1234; t. 134, p. 208. 
73176°—smM 1914 35 
