Monthly Microscopical! PROGRESS OF MICROSCOPICAL SCIENCE. 167 
periosteum. The two cases died, but at sufficient time after the ope- 
ration to show the advantages of the remedy. Both were cases of 
resection of the elbow-joint. One died eighteen months and the other 
a year after the operation. 
Death of Albrecht Von Graefe-—The ‘ Lancet’ records the death of 
this distinguished man. Besides some researches which may be con- 
sidered to give him standing as a microscopist, he had done much to 
advance our knowledge of eye structure. Indeed he may safely be 
said to have been the first ophthalmic surgeon in the world. 
Death of Minute Organisms.—A paper which is of some interest, 
though containing many facts which are now regarded as absolutely 
proven by the advanced microscopist, is published in the ‘ Lancet,’ 
August 6th. Mr. John Dougall, M.B., is the author, and he states that 
the number of genera of organisms operated on by him is undoubtedly 
small; still they represent a number of facts, forming a quota of the 
truth. The entomostraca, though not microscopic, are yet very small 
in size, being about =1,th of an inch in their short diameter. These 
were added to the list from their being easily procured, and also for 
the purpose of comparing their susceptibility to the action of the 
poisons with that of the other organisms. A considerable number of 
them happened to be pregnant females, having their purple ova-sacs 
attached externally at the free abdominal extremity, which were soon 
shed or aborted under the influence of the poison. The species was 
exclusively Cyclops quadricornis (Miller), taken in fresh water. The 
infusoria were obtained from water in which hay had been steeped 
for two weeks. The spermatozoa were human, and regarding these it 
may be stated that it has been ascertained by Kolliker, quoted in the 
‘Cyclopedia of Natural History, “that the over-dilution of the semen 
with water causes the filaments to form loops, and their motions to 
cease, and that they are revivified by the addition of such substances 
as albumen, syrup, &c.” My observations on the spermatozoa have 
been-such as to make me accept the first part of this statement with 
some qualification. Probably were the semen very largely diluted 
with water, the phenomena would be such as described by Kolliker ; 
but it has been found that two parts of water added to one part of the 
spermatic fluid has only the effect of curtailing the vivacity of the 
filaments, considerable motion being still quite perceptible. In regard 
to the latter part of Kélliker’s statement—namely, “that the filaments 
can be revivified by the addition of albumen, syrup, &c., when ren- 
dered motionless in dilute aqueous solutions,” it was understood that 
he meant solutions which are very dilute ; and as most of the substances 
which have been stated as causing the death of the filaments may be 
considered as very dilute, it was assumed that the cessation of motion 
might be the result of such great dilution, and consequently that, 
according to Kélliker, the addition of syrup or albumen would prove 
whether the filaments were merely motionless or actually dead. In 
each case, then, after it was seen that they had ceased to move, an 
attempt at resuscitation was made by adding a little syrup or albumen, 
and it may be stated that in no case was motion renewed. A uniform 
method in bringing the various poisonous menstrua in contact with 
VOL. IY. N 
