3 53 
SHORT NOTES ON PROFESSIONAL SUBJECTS. 
91. Explosive Compound. “ Lithofracteur.”— Director of Artillery, 
38. 3. 71, forwards, for record, a memorandum, dated 31. 3. 71, by Mr. Abel, 
Chemist to War Department, recording the nature and composition of an explosive 
agent known as “ lithofracteur,” used in the Prussian military service for purposes 
similar to those where compressed gunpowder is employed, an article upon which 
appeared in the “Times” of 30. 3. 71, written by a military correspondent at 
Versailles. 
The specimen analysed by Mr. Abel in December 1869, consisted of a flattened 
roll, 4 ins. long, resembling in colour coarse damp clay in its mechanical condition, 
and enclosed in several folds of thin paper saturated with nitro-glycerine absorbed 
from the mass thus enclosed. The following is the composition :— 
Nitro-glycerine. 42 parts. 
Nitrate of soda. 25 « 
Sulphur. 4 « 
Sand, silicious earth, sawdust, and coarsely powdered coal ... 29 /; 
Total. 100 
This so-called “lithofracteur” differs from nitro-glycerine preparation termed 
“ dynamite,” chiefly in containing a proportion of gunpowder constituents—viz., 
saltpetre, carbon, and sulphur, mixed up with the other ingredients. 
He states that from the analysis of a second sample it would appear that the 
substance is very crudely mixed, and varies considerably in composition, and that 
there is no reason whatever to consider this preparation an improvement upon 
dynamite. It would certainly not be more violent in action; and the circumstance 
that in any application of it the hands of the operators must become soiled with 
the poisonous nitro-glycerine, constitutes a very serious objection. 
93. Hydraulic Lifting Jack.* —It has been noticed that artillerymen working 
this jack, neglect to loosen the screw plug in the head. If this is not done, air 
cannot enter when the jack is required to be lowered, and it remains in a raised 
position. When this occurs it is supposed that the jack is out of order. 
The screw plug should be replaced when the jack is to be transported. 
It may be well to use caution in lowering great weights by hydraulic jacks. For 
instance, if the breach of a gun is supported on two jacks at the end of a beam, and 
one is lowered quickly, before the other, the gun may roll over; or if the breech is on 
kidding, and the muzzle is lowered rapidly, and beyond 4° depression, the gun is 
apt to upset the skidding and slip to the front. These accidents are not likely to 
occur with screw jacks, considerable time being required to lower a weight. 
* Vide Carriage Department lithograph, No. 79, 
