Connective Substances. By T. E. Satterthwaite. 243 
cases better results are obtained by the use of chloride of gold. The 
method is as follows : Freeze a thin portion of a tendon, then make 
the thinnest possible section, acidulate it slightly, and then immerse 
in a one-half per cent, solution of chloride of gold, until a straw- 
yellow colour has been obtained, and then immerse in a one-fourth 
per cent, solution of dilute acetic acid, and expose to the sunhght 
until it is purple or reddish ; this will take a variable time, and is 
not always successful, for reasons which are not easy to understand. 
This is the ordinary method now in general use. At considerable 
distances from one another there will be seen small dark bodies, 
which are the corpuscles already described. It is difficult to show 
that these corpuscles are connected together. To isolate them, 
take a small piece of young tendon tissue, immerse three or four 
days in a 10 per cent, solution of common salt, and then tease. 
In this way the cells may be liberated, and they will be found to 
be irregularly flattened plates. Silver or gold, the latter especially, 
is generally necessary to show the nuclei in old tendons. The 
same method shows the fibrillated tissue to advantage. These 
latter methods will also show that the tendon bundles are covered, 
more or less completely, with a delicate epithelium (endothelium). 
The tendon corpuscles do not by any means form a connected 
sheath for the bundles. In very young tendons the corpuscles are 
very near together, though even then they only form a partial in- 
vestment for the bundles ; but as the tendon grows older the cor- 
puscles become smaller, withdraw from one another, and sometimes 
almost disappear. 
6. Fat-Tissue. — This is a form of tissue that seems to be the 
ordinary fibrillated connective tissue in a changed condition. It 
becomes the deposit for oil which appears to fill the corpuscles, 
making them swell out enormously, as already stated. An ex- 
cellent way of showing this tissue consists in making a section of a 
portion of fatty tissue that has been hardened in alcohol or Miiller's 
fluid, or both. The appearances will, in this way, be well shown. 
After immersion in an acid solution, it will be seen that the fatty 
acids crystallize in the centre of the sac. 
The nature of the evidence that the fat-corpuscles are really 
the trans Ibrmed corpuscles of the fibrous tissues is as follows : They 
occupy the same position, being in rows between the bundles and 
corresponding in position to the other corpuscles that we have 
mentioned ; a few oil- drops at first appear, then others, until 
finally they coalesce into a single large drop which fills the 
envelope ; if fat-tissue be pressed and the oil escapes, the walls of 
the fat-corpuscles collapse, and then the flattened plates (nuclei) 
may be observed on the side of the cavity. 
Waldeyer (loc. eit.) believes that there is a peculiar corpuscle, 
three to five times the size of a lymphoid corpuscle and roundish, 
